Windows Explorer
Encyclopedia
This article is about the Windows file system browser. For the similarly named web browser, see Internet Explorer
Windows Explorer is a file manager
application that is included with releases of the Microsoft Windows
operating system
from Windows 95
onwards. It provides a graphical user interface
for accessing the file system
s. It is also the component of the operating system that presents many user interface items on the monitor
such as the taskbar
and desktop
. Controlling the computer is possible without Windows Explorer running (for example, the File | Run command in Task Manager on NT-derived versions of Windows will function without it, as will commands typed in a command prompt window). Located in the
,
as a replacement for the Windows 3.x
File Manager. It could be accessed by double-clicking the new My Computer desktop icon, or launched from the new Start Menu
that replaced the earlier Program Manager
. There is also a shortcut key combination: Windows key
+ E. Successive versions of Windows (and in some cases, Internet Explorer
) introduced new features and capabilities, removed other features, and generally progressed from being a simple file system navigation tool into a task-based file management system.
While “Windows Explorer” is a term most commonly used to describe the file management aspect of the operating system, the Explorer process also houses the operating system’s search functionality and File Type associations (based on filename extension
s), and is responsible for displaying the desktop
icons
, the Start Menu
, the Taskbar
, and the Control Panel
. Collectively, these features are known as the Windows shell
.
After a user logs in, the explorer process is created by userinit process. Userinit performs some initialization of the user environment (such as running the login script and applying group policies) and then looks in the registry at the Shell value and creates a process to run the system-defined shell—by default, Explorer.exe. Then Userinit exits. This is the reason why Explorer.exe is shown by various process explorers with no parent—its parent has exited.
users: 26 May 1995 and 8 August 1995. Both held Windows Explorer builds of 3.51.1053.1. The Shell Technology Preview program never saw a final release under NT 3.51. The entire program was moved across to the Cairo
development group who finally integrated the new shell design into the NT code with the release of NT 4.0 in July 1996.
With the release of the Windows Desktop Update
(packaged with Internet Explorer 4.0 as an optional component, and included in Windows 98
), Windows Explorer became "integrated" with Internet Explorer, most notably with the addition of navigation arrows (back and forward) for moving between recently visited directories, as well as Internet Explorer’s Favorites menu. At the time these changes raised antitrust
concerns about the incorporation of what was seen as an application feature, but this feature has since been emulated by most other file browsers.
An address bar was also added to Windows Explorer, which a user could type in directory paths directly, and be taken to that folder. It also operated as a URL
bar for Internet addresses; web pages would open in the main portion of the window.
Another feature that was based on Internet Explorer technology was customized folders. Such folders contained a hidden web page that controlled the way the Windows Explorer displayed the contents of the folder. This feature proved to have security vulnerabilities due to its reliance on ActiveX
objects and scripting
, and was removed with the introduction of Windows XP
.
Other new features:
The "Web-style" folders view, with the left Explorer pane displaying details for the object currently selected, is turned on by default. For certain file types, such as pictures and media files, a preview is also displayed in the left pane. The Windows 2000 Explorer featured an interactive media player as the previewer for sound and video files. However, such a previewer can be enabled in Windows Me
through the use of folder customization templates Windows Explorer in Windows 2000 and Windows Me allows for custom thumbnail previewers and tooltip
handlers. The default file tooltip displays file title, author, subject and comments; this metadata may be read from a special NTFS
stream, if the file is on an NTFS volume, or from an OLE structured storage
stream, if the file is a structured storage document. All Microsoft Office
documents since Office 95 make use of structured storage
, so their metadata is displayable in the Windows 2000 Explorer default tooltip
. File shortcuts
can also store comments which are displayed as a tooltip when the mouse hovers over the shortcut.
The right-hand pane, which usually just lists files and folders, can also be customized. For example, the contents of the system folders aren't displayed by default, instead showing in the right pane a warning to the user that modifying the contents of the system folders could harm their computer. It's possible to define additional Explorer panes by using DIV elements in folder template files. This feature was abused by computer virus
es that employed malicious scripts, Java
applets, or ActiveX
controls in folder template files as their infection vector. Two such viruses are VBS/Roor-C and VBS.Redlof.a.
Other Explorer UI elements that can be customized include columns in "Details" view, icon overlays, and search providers: the new DHTML-based search pane is integrated into Windows 2000 Explorer, unlike the separate search dialog found in all previous Explorer versions.
Search capabilities were added, offering full-text searches of documents, with options to filter by date (including arbitrary ranges like “modified within the last week”), size, and file type. The Indexing Service
has also been integrated into the operating system and the search pane built into Explorer allows searching files indexed by its database. The ability to customize the standard toolbar buttons was also added.
There were significant changes made to Windows Explorer in Windows XP
, both visually and functionally. Microsoft focused especially on making Explorer more discoverable and task-based, as well as adding a number of features to reflect the growing use of a computer as a “digital hub”.
Windows Explorer in Windows Server 2003
contains all the same features as Windows XP, but the task panes and search companion are disabled by default.
Every folder also has “File and Folder Tasks”, offering options to create new folders, share a folder on the local network, publish files or folders to a web site, and other common tasks like copying, renaming, moving, and deleting files or folders. File types that have identified themselves as being printable also have an option listed to print the file.
Underneath “File and Folder Tasks” is “Other Places”, with links to other common locations such as “My Computer”, “Control Panel”, and “My Documents”. These also change depending on what folder the user was in, leading to some criticism of Microsoft for not being consistent in displaying navigation choices.
Underneath “Other Places” is a “Details” pane which gives additional information – typically file size and date, but depending on the file type, a thumbnail preview, author, image dimensions, or other details.
The “Folders” button on the Windows Explorer toolbar toggles between the traditional tree view of folders, and the task pane. Users can get rid of the task pane or restore it using the sequence: Tools – Folder Options – General – Show Common Tasks/Use Windows Classic Folders.
Microsoft introduced animated “Search Companions” in an attempt to make searching more engaging and friendly; the default character is a puppy named Rover (previously used in Microsoft BOB), with three other characters (Merlin the magician, Earl the surfer, and Courtney) also available. These search companions bear a great deal of similarity to Microsoft Office
’s Office Assistant
s, even incorporating “tricks” and sound effects.
The search capability itself is fairly similar to Windows Me and Windows 2000, with one major addition: Search can also be instructed to search only files that are categorically “Documents” or “Pictures, music and video"; this feature is noteworthy largely because of how Windows determines what types of files can be classified under these categories. In order to maintain a relevant list of file types, Windows Explorer connects to Microsoft and downloads a set of XML files that define what these file types are. While harmless in itself, this feature caught the attention of a number of privacy advocates, and users with firewall software installed, who felt it was unnecessary for Windows to connect to Microsoft’s servers whenever a local search was performed.
Windows XP improves image preview in Explorer by offering a Filmstrip view. “Back” and “Previous” buttons facilitate navigation through the pictures, and a pair of “Rotate” buttons offer 90-degree clockwise and counter-clockwise (lossy
) rotation of images. Aside from the Filmstrip view mode, there is a 'Thumbnails' mode, which displays thumbnail
-sized images in the folder. A Folder containing images will also show thumbnails of four of the images from that folder overlaid on top of a large folder icon.
Windows Explorer also contains modifications in the visualization of files on a computer. A new addition to Windows Explorer in Vista and Server 2008 is the Details pane, which displays metadata and information relating to the currently selected file or folder. The Details pane will also display a thumbnail of the file or an icon of the filetype if the file does not contain visual information. Furthermore, different imagery is overlayed on thumbnails to give more information about the file, such as a picture frame around the thumbnail of an image file, or a filmstrip on a video file. Thumbnails can be zoomed on.
The Details pane also allows for the change of some textual metadata such as 'Author' and 'Title' in files that support them within Windows Explorer. A new type of metadata called tags allows users to add descriptive terms to documents for easier categorization and retrieval. Some files support open metadata, allowing users to define new types of metadata for their files. Out-of-the-box, Windows Vista and Windows Server 2008 supports Microsoft Office documents and most audio and video files. Support for other file types can however be added by writing specialized software to retrieve the metadata at the shell’s request. Metadata stored in a file’s alternate (secondary) stream only on NTFS volumes cannot be viewed and edited through the 'Summary' tab of the file’s properties anymore. Instead, all metadata is stored inside the file, so that it will always travel with the file and not be dependent on the file system.
and Windows Server 2008 also introduces a new layout. The Task Panes from Windows XP are replaced with a toolbar on top and a Navigation pane on the left. The Navigation pane contains commonly accessed folders and prepopulated Search folders. Seven different views are available to view files and folders, namely, List, Details, Small icons, Medium icons, Large icons, Extra large icons or Tiles. Automatic folder type discovery automatically detects the contents of a folder and display the correct detail settings. File and folder actions such as Cut, Copy, Paste, Undo, Redo, Delete, Rename and Properties are built into a dropdown menu which appears when the Organize button is clicked. It is also possible to change the layout of the Explorer window by using the Organize button. Users can select whether to display Classic Menus, a Search Pane, a Preview Pane, a Reading Pane, and/or the Navigation Pane. The Preview pane, allows for previewing files (viewing documents and playing media files) in addition to the Details pane. Also, Explorer can show a preview for any image format if the necessary codec for the format is installed in the Windows Imaging Component
.
The address bar has been replaced by a breadcrumbs
bar for easier navigation. It shows the full path to the current location. Clicking any location in the path hierarchy takes the user to that level, instead of repeatedly pressing the Back button. This is similar to what is possible in Windows XP by pressing the small down-arrow next to “Back” and selecting any folder from a list of previously accessed folders. It is also possible to navigate to any subfolder of the current folder using the arrow to the right of the last item, or to click in the space to the right of this to copy or edit the path manually. As with many other Microsoft-made Windows Vista applications, the menu bar is hidden by default. Pressing the Alt key makes the menu bar appear.
Check boxes in Windows Explorer allow the selection of multiple files. Free and used space on all drives is shown in horizontal indicator bars. Icons of various sizes are supported – 16 x 16, 24 x 24, 32 x 32, 48 x 48, 64 x 64, 96 x 96, 128 x 128 and 256 x 256. Windows Explorer can zoom the icons in and out using a slider or by holding down the Ctrl key and using the mouse scrollwheel.
for Windows XP, Internet Explorer is no longer integrated with Windows Explorer. Unlike older versions, Windows Explorer does not host Internet Explorer controls in its own process, rather it launches a new process when necessary. In Windows Vista and Server 2008 (and in Windows XP as well if IE7 or 8 is installed), Windows Explorer no longer displays web pages, and IE7 does not support use as a file manager, although one will separately launch the other as necessary.
When moving or copying files from one folder to another, if two files have the same name, an option is now available to rename the file; in previous versions of Windows, the user was prompted to choose either a replacement or cancel moving the file. Also, when renaming a file, Explorer only highlights the filename without selecting the extension. Renaming multiple files is quicker as pressing Tab automatically renames the existing file or folder and opens the file name text field for the next file for renaming. Shift+Tab allow renaming in the same manner upwards.
Support for burning data on DVDs (DVD±R, DVD±R DL, DVD±R RW) in addition to CDs and DVD-RAM
using version 2.0 of the Image Mastering API
was added.
In case a file is in use by another application, Windows Explorer informs users to close the application and retry the file operation. Also, a new interface 'IFileIsInUse' is introduced into the API which developers can use to let other applications switch to the main window of the application that has the file open or simply close the file from the “File In Use” dialog. If the running application exposes these operations by means of the IFileInUse interface, Windows Explorer, upon encountering a locked file, allows the user to close the file or switch to the application from the dialog box itself.
file (compressed folder). The Toolbar button in Explorer to go up one folder from the current folder has been removed (the function still exists however, one can move up a folder by pressing Alt+↑). Although still fully available from the menus and keyboard shortcuts, toolbar buttons for Cut, Copy, Paste, Undo, Delete, Properties and some others are no longer available. The Menu Bar is also hidden by default, but is still available by pressing the Alt key, or changing its visibility in the layout options. Several other features are removed such as showing the size on the status bar without selecting items, storing metadata
in NTFS secondary streams, the IColumnProvider interface which allowed addition of custom columns to Explorer and folder background customization using desktop.ini.
The option "Managing pairs of Web pages and folders" is also removed, and the user has no way of telling Vista that a .html file and the folder with the same name that was created when saving a complete web page from IE should be treated separately, that is, you cannot delete the folder without deleting the html file as well.
A solution to this is provided on (http://windowsxp.mvps.org/webpairs.htm). After the webpairs.reg file has been merged into the registry, the "Managing pairs of Web pages and folders" option is available in the Folder Options View tab.
The ability to right-click a folder and hit "Search" has been removed, as have the fields to fill in to customize your search. Now you must highlight the folder you wish to search and enter your keywords in the search field in the top right corner, however, you may not enter any other search parameters until after the system has finished searching the entire folder based on that one (or few) keywords. Only then will the "Advanced Search" button appear, allowing you to enter further search parameters. This situation can be bypassed. While in Windows Explorer, the F3 key is hit. This should bring up the "Advanced Search" box.
By default, a new user account in Windows 7 contains four libraries, for different file types: Documents, Music, Pictures, and Videos. They are configured to include the user's profile folders for these respective file types, as well as the computer's corresponding Public folders.
In addition to aggregating multiple storage locations, Libraries enable Arrangement Views and Search Filter Suggestions. Arrangement Views allow you to pivot your view of the library's contents based on metadata. For example, selecting the "By Month" view in the Pictures library will display photos in stacks, where each stack represents a month of photos based on the date they were taken. In the Music library, the "By Artist" view will display stacks of albums from the artists in your collection, and browsing into an artist stack will then display the relevant albums.
Search Filter Suggestions are a new feature of the Windows 7 and Windows Server 2008 R2 Explorer's search box. When the user clicks in the search box, a menu shows up below it showing recent searches as well as suggested Advanced Query Syntax filters that the user can type. When one is selected (or typed in manually), the menu will update to show the possible values to filter by for that property, and this list is based on the current location and other parts of the query already typed. For example, selecting the "tags" filter or typing "tags:" into the search box will display the list of possible tag values which will return search results.
Arrangement Views and Search Filter Suggestions are database-backed features which require that all locations in the Library be indexed by the Windows Search service. Local disk locations must be indexed by the local indexer, and Windows Explorer will automatically add locations to the indexing scope when they are included in a library. Remote locations can be indexed by the indexer on another Windows 7 and Windows Server 2008 R2 machine, on a Windows machine running Windows Search 4 (such as Windows Vista or Windows Home Server), or on another device that implements the MS-WSP remote query protocol.
definition. The federated location description (called a Search Connector) is provided as a
of Microsoft Corporation announced in a blog post that Windows Explorer for Windows 8 will use the ribbon UI used by most other Microsoft products.
objects that plug-in the extended functionality into Windows Explorer. Shell extensions can be in the form of shell extension handlers, toolbars or even namespace extensions that allow certain folders (or even non-filesystem objects such as the images scanned by a scanner) to be presented as a Special Folder
. Windows Explorer up to Windows XP also allows metadata
for files to be added as NTFS
Alternate Data Streams, separate from the data stream for the file.
Shell extension handlers are queried by the shell beforehand for modifying the action the shell takes. They can be associated on a per-file type basis - where they will show up only when a particular action takes place on a particular file type - or on a global basis - which are always available. The shell supports the following extension handlers:
Namespace extensions are used by Explorer to either display some data - which are not persisted as files - in a folder-like view or to present data in a way that is different from their organization on the file system. This feature can be exploited by a Relational File System like liquidFOLDERS or Tabbles , clones of the ill-fated Microsoft WinFS
. Special Folders
, such as My Computer and Network Places in Windows Explorer are implemented this way, as are Explorer views that let items in a mobile phone
or digital camera
be explored. Source-control system
s that use Explorer to browse source repositories also use Namespace extensions to allow Explorer to browse the revisions. To implement a namespace extension, the
While Windows Explorer natively exposes the extensibility points as COM
interfaces, .NET Framework
can also be used to write extensions, using the COM Interop
functionality of .NET Framework. While Microsoft itself makes available extensions - such as the Photo Info tool - which are authored using .NET Framework
, they currently recommend against writing managed
shell extensions, as only one instance of the CLR
(prior to version 4.0) can be loaded per-process. This behavior would cause conflicts if multiple managed add-ins, targeting different versions of the CLR, are attempted to be run simultaneously.
, do not have this limitation.
Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
Windows Explorer is a file manager
File manager
A file manager or file browser is a computer program that provides a user interface to work with file systems. The most common operations performed on files or groups of files are: create, open, edit, view, print, play, rename, move, copy, delete, search/find, and modify file attributes, properties...
application that is included with releases of the Microsoft Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
operating system
Operating system
An operating system is a set of programs that manage computer hardware resources and provide common services for application software. The operating system is the most important type of system software in a computer system...
from Windows 95
Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products...
onwards. It provides a graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...
for accessing the file system
File system
A file system is a means to organize data expected to be retained after a program terminates by providing procedures to store, retrieve and update data, as well as manage the available space on the device which contain it. A file system organizes data in an efficient manner and is tuned to the...
s. It is also the component of the operating system that presents many user interface items on the monitor
Computer display
A monitor or display is an electronic visual display for computers. The monitor comprises the display device, circuitry, and an enclosure...
such as the taskbar
Taskbar
In computing, a taskbar is a bar displayed on a full edge of a GUI desktop that is used to launch and monitor running applications. Microsoft incorporated a taskbar in Windows 95 and it has been a defining aspect of Microsoft Windows's graphical user interface ever since. Some desktop environments,...
and desktop
Desktop
Desktop refers to the surface of a desk.The term has been adopted as an adjective to distinguish office appliances which can be fitted on top of a desk, from larger equipment covering its own area on the floor....
. Controlling the computer is possible without Windows Explorer running (for example, the File | Run command in Task Manager on NT-derived versions of Windows will function without it, as will commands typed in a command prompt window). Located in the
C:\Windows directory, it is sometimes referred to as the Windows ShellWindows Shell
The Windows shell is the main graphical user interface in Microsoft Windows, and since Windows 95 hosted by Windows Explorer. The Windows shell includes well-known Windows components such as the Taskbar and the Start menu...
,
explorer.exe, or simply “Explorer”.Overview
The Windows Explorer was first included with Windows 95Windows 95
Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products...
as a replacement for the Windows 3.x
Windows 3.x
Windows 3.x can refer to either an individual or all of the following versions of Microsoft Windows:*Windows 3.0*Windows 3.1x*Windows 3.2...
File Manager. It could be accessed by double-clicking the new My Computer desktop icon, or launched from the new Start Menu
Start menu
The Start Menu and Start Button are user interface elements used in the later versions of the Microsoft Windows operating systems and in some X window managers...
that replaced the earlier Program Manager
Program Manager
Program Manager is the shell of Windows 3.x and Windows NT 3.x operating systems. This shell exposed a task-oriented graphical user interface , consisting of icons arranged into program groups. It replaced MS-DOS Executive, a file manager, as the default Windows shell.The program derives from the...
. There is also a shortcut key combination: Windows key
Windows key
The Windows logo key—also known as the Windows key, the home key, the meta key, the start key, MOD4, or the flag key —is a keyboard key which was originally introduced on the Microsoft Natural keyboard before the release of Windows 95. This key became a standard key on PC keyboards...
+ E. Successive versions of Windows (and in some cases, Internet Explorer
Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
) introduced new features and capabilities, removed other features, and generally progressed from being a simple file system navigation tool into a task-based file management system.
While “Windows Explorer” is a term most commonly used to describe the file management aspect of the operating system, the Explorer process also houses the operating system’s search functionality and File Type associations (based on filename extension
Filename extension
A filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
s), and is responsible for displaying the desktop
Desktop environment
In graphical computing, a desktop environment commonly refers to a style of graphical user interface derived from the desktop metaphor that is seen on most modern personal computers. These GUIs help the user in easily accessing, configuring, and modifying many important and frequently accessed...
icons
Icon (computing)
A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an...
, the Start Menu
Start menu
The Start Menu and Start Button are user interface elements used in the later versions of the Microsoft Windows operating systems and in some X window managers...
, the Taskbar
Taskbar
In computing, a taskbar is a bar displayed on a full edge of a GUI desktop that is used to launch and monitor running applications. Microsoft incorporated a taskbar in Windows 95 and it has been a defining aspect of Microsoft Windows's graphical user interface ever since. Some desktop environments,...
, and the Control Panel
Control Panel (Windows)
The Control Panel is a part of the Microsoft Windows graphical user interface which allows users to view and manipulate basic system settings and controls via applets, such as adding hardware, adding and removing software, controlling user accounts, and changing accessibility options...
. Collectively, these features are known as the Windows shell
Windows Shell
The Windows shell is the main graphical user interface in Microsoft Windows, and since Windows 95 hosted by Windows Explorer. The Windows shell includes well-known Windows components such as the Taskbar and the Start menu...
.
After a user logs in, the explorer process is created by userinit process. Userinit performs some initialization of the user environment (such as running the login script and applying group policies) and then looks in the registry at the Shell value and creates a process to run the system-defined shell—by default, Explorer.exe. Then Userinit exits. This is the reason why Explorer.exe is shown by various process explorers with no parent—its parent has exited.
History
In 1995, Microsoft first released test versions of a shell refresh, named the Shell Technology Preview, and often referred to informally as "NewShell". The update was designed to replace the Windows 3.x Program Manager/File Manager based shell with Windows Explorer. The release provided capabilities quite similar to that of the Windows "Chicago" (codename for Windows 95) shell during its late beta phases, however was intended to be nothing more than a test release. There were two public releases of the Shell Technology Preview, made available to MSDN and CompuServeCompuServe
CompuServe was the first major commercial online service in the United States. It dominated the field during the 1980s and remained a major player through the mid-1990s, when it was sidelined by the rise of services such as AOL with monthly subscriptions rather than hourly rates...
users: 26 May 1995 and 8 August 1995. Both held Windows Explorer builds of 3.51.1053.1. The Shell Technology Preview program never saw a final release under NT 3.51. The entire program was moved across to the Cairo
Cairo (operating system)
Cairo was the code name for a project at Microsoft from 1991 to 1996. Its charter was to build technologies for a next generation operating system that would fulfill Bill Gates' vision of "information at your fingertips." Cairo never shipped, although portions of its technologies have since...
development group who finally integrated the new shell design into the NT code with the release of NT 4.0 in July 1996.
Windows 98 and Windows Desktop Update
Windows Desktop Update
Microsoft's Windows Desktop Update was an optional feature included with Internet Explorer 4 , which introduced several updated shell features to the Windows 95 and Windows NT 4.0 operating systems...
(packaged with Internet Explorer 4.0 as an optional component, and included in Windows 98
Windows 98
Windows 98 is a graphical operating system by Microsoft. It is the second major release in the Windows 9x line of operating systems. It was released to manufacturing on 15 May 1998 and to retail on 25 June 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid...
), Windows Explorer became "integrated" with Internet Explorer, most notably with the addition of navigation arrows (back and forward) for moving between recently visited directories, as well as Internet Explorer’s Favorites menu. At the time these changes raised antitrust
Antitrust
The United States antitrust law is a body of laws that prohibits anti-competitive behavior and unfair business practices. Antitrust laws are intended to encourage competition in the marketplace. These competition laws make illegal certain practices deemed to hurt businesses or consumers or both,...
concerns about the incorporation of what was seen as an application feature, but this feature has since been emulated by most other file browsers.
An address bar was also added to Windows Explorer, which a user could type in directory paths directly, and be taken to that folder. It also operated as a URL
Uniform Resource Locator
In computing, a uniform resource locator or universal resource locator is a specific character string that constitutes a reference to an Internet resource....
bar for Internet addresses; web pages would open in the main portion of the window.
Another feature that was based on Internet Explorer technology was customized folders. Such folders contained a hidden web page that controlled the way the Windows Explorer displayed the contents of the folder. This feature proved to have security vulnerabilities due to its reliance on ActiveX
ActiveX
ActiveX is a framework for defining reusable software components in a programming language-independent way. Software applications can then be composed from one or more of these components in order to provide their functionality....
objects and scripting
Scripting language
A scripting language, script language, or extension language is a programming language that allows control of one or more applications. "Scripts" are distinct from the core code of the application, as they are usually written in a different language and are often created or at least modified by the...
, and was removed with the introduction of Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
.
Other new features:
- The ability to add other toolbars to the task bar, the most visible of these being Quick Launch.
- “HTML Desktop”, which made it possible to turn the desktop background itself into a web page.
- Single-click activation of icons in Windows Explorer, adhering to a web page paradigm.
- Desktop ChannelsActive DesktopActive Desktop was a feature of Microsoft Internet Explorer 4.0's optional Windows Desktop Update that allows the user to add HTML content to the desktop, along with some other features. This function was intended to be installed on the then-current Windows 95 operating system...
. - New virtual folderVirtual folderIn computing, a virtual folder generally denotes an organizing principle for files that is not dependent on location in a hierarchical directory tree...
s for Scheduled Tasks and Web Folders
Windows Me and Windows 2000
Windows Me
Windows Millennium Edition, or Windows Me , is a graphical operating system released on September 14, 2000 by Microsoft, and was the last operating system released in the Windows 9x series. Support for Windows Me ended on July 11, 2006....
through the use of folder customization templates Windows Explorer in Windows 2000 and Windows Me allows for custom thumbnail previewers and tooltip
Tooltip
The tooltip or infotip is a common graphical user interface element. It is used in conjunction with a cursor, usually a mouse pointer. The user hovers the cursor over an item, without clicking it, and a tooltip may appear—a small "hover box" with information about the item being hovered...
handlers. The default file tooltip displays file title, author, subject and comments; this metadata may be read from a special NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7....
stream, if the file is on an NTFS volume, or from an OLE structured storage
Structured storage
COM Structured Storage is a technology developed by Microsoft as part of its Windows operating system for storing hierarchical data within a single file...
stream, if the file is a structured storage document. All Microsoft Office
Microsoft Office
Microsoft Office is a non-free commercial office suite of inter-related desktop applications, servers and services for the Microsoft Windows and Mac OS X operating systems, introduced by Microsoft in August 1, 1989. Initially a marketing term for a bundled set of applications, the first version of...
documents since Office 95 make use of structured storage
Structured storage
COM Structured Storage is a technology developed by Microsoft as part of its Windows operating system for storing hierarchical data within a single file...
, so their metadata is displayable in the Windows 2000 Explorer default tooltip
Tooltip
The tooltip or infotip is a common graphical user interface element. It is used in conjunction with a cursor, usually a mouse pointer. The user hovers the cursor over an item, without clicking it, and a tooltip may appear—a small "hover box" with information about the item being hovered...
. File shortcuts
Computer shortcut
A file shortcut in Microsoft Windows is a small file containing a target URI or GUID to an object, or the name of a target program file that the shortcut represents. The shortcut might additionally specify parameters to be passed to the target program when it is run. Each shortcut can have its own...
can also store comments which are displayed as a tooltip when the mouse hovers over the shortcut.
The right-hand pane, which usually just lists files and folders, can also be customized. For example, the contents of the system folders aren't displayed by default, instead showing in the right pane a warning to the user that modifying the contents of the system folders could harm their computer. It's possible to define additional Explorer panes by using DIV elements in folder template files. This feature was abused by computer virus
Computer virus
A computer virus is a computer program that can replicate itself and spread from one computer to another. The term "virus" is also commonly but erroneously used to refer to other types of malware, including but not limited to adware and spyware programs that do not have the reproductive ability...
es that employed malicious scripts, Java
Java (programming language)
Java is a programming language originally developed by James Gosling at Sun Microsystems and released in 1995 as a core component of Sun Microsystems' Java platform. The language derives much of its syntax from C and C++ but has a simpler object model and fewer low-level facilities...
applets, or ActiveX
ActiveX
ActiveX is a framework for defining reusable software components in a programming language-independent way. Software applications can then be composed from one or more of these components in order to provide their functionality....
controls in folder template files as their infection vector. Two such viruses are VBS/Roor-C and VBS.Redlof.a.
Other Explorer UI elements that can be customized include columns in "Details" view, icon overlays, and search providers: the new DHTML-based search pane is integrated into Windows 2000 Explorer, unlike the separate search dialog found in all previous Explorer versions.
Search capabilities were added, offering full-text searches of documents, with options to filter by date (including arbitrary ranges like “modified within the last week”), size, and file type. The Indexing Service
Windows indexing service
Indexing Service was a Windows service that maintained an index of most of the files on a computer to improve searching performance on PCs and corporate computer networks. It updated indexed without user intervention...
has also been integrated into the operating system and the search pane built into Explorer allows searching files indexed by its database. The ability to customize the standard toolbar buttons was also added.
Windows XP and Windows Server 2003
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...
, both visually and functionally. Microsoft focused especially on making Explorer more discoverable and task-based, as well as adding a number of features to reflect the growing use of a computer as a “digital hub”.
Windows Explorer in Windows Server 2003
Windows Server 2003
Windows Server 2003 is a server operating system produced by Microsoft, introduced on 24 April 2003. An updated version, Windows Server 2003 R2, was released to manufacturing on 6 December 2005...
contains all the same features as Windows XP, but the task panes and search companion are disabled by default.
Task Pane
The task pane is displayed on the left-hand side of the window instead of the traditional folder tree view. It presents the user with a list of common actions and destinations that are relevant to the current directory or file(s) selected. For instance, when in a directory containing mostly pictures, a set of “Picture tasks” is shown, offering the options to display these pictures as a slide show, to print them out, or to go online to order prints. Conversely, a folder containing music files would offer options to play those files in a media player, or to go online to purchase music. Windows XP had a Media bar but it was removed with SP1. The Media Bar was only available with Windows XP RTM.Every folder also has “File and Folder Tasks”, offering options to create new folders, share a folder on the local network, publish files or folders to a web site, and other common tasks like copying, renaming, moving, and deleting files or folders. File types that have identified themselves as being printable also have an option listed to print the file.
Underneath “File and Folder Tasks” is “Other Places”, with links to other common locations such as “My Computer”, “Control Panel”, and “My Documents”. These also change depending on what folder the user was in, leading to some criticism of Microsoft for not being consistent in displaying navigation choices.
Underneath “Other Places” is a “Details” pane which gives additional information – typically file size and date, but depending on the file type, a thumbnail preview, author, image dimensions, or other details.
The “Folders” button on the Windows Explorer toolbar toggles between the traditional tree view of folders, and the task pane. Users can get rid of the task pane or restore it using the sequence: Tools – Folder Options – General – Show Common Tasks/Use Windows Classic Folders.
Search companion
Microsoft Office
Microsoft Office is a non-free commercial office suite of inter-related desktop applications, servers and services for the Microsoft Windows and Mac OS X operating systems, introduced by Microsoft in August 1, 1989. Initially a marketing term for a bundled set of applications, the first version of...
’s Office Assistant
Office Assistant
The Office Assistant was a Microsoft Office feature to assist users by way of an interactive animated character, which interfaced with the Office help content. It used technology initially from Microsoft Bob and later Microsoft Agent, offering advice based on Bayesian algorithms...
s, even incorporating “tricks” and sound effects.
The search capability itself is fairly similar to Windows Me and Windows 2000, with one major addition: Search can also be instructed to search only files that are categorically “Documents” or “Pictures, music and video"; this feature is noteworthy largely because of how Windows determines what types of files can be classified under these categories. In order to maintain a relevant list of file types, Windows Explorer connects to Microsoft and downloads a set of XML files that define what these file types are. While harmless in itself, this feature caught the attention of a number of privacy advocates, and users with firewall software installed, who felt it was unnecessary for Windows to connect to Microsoft’s servers whenever a local search was performed.
Image handling
Lossy data compression
In information technology, "lossy" compression is a data encoding method that compresses data by discarding some of it. The procedure aims to minimize the amount of data that need to be held, handled, and/or transmitted by a computer...
) rotation of images. Aside from the Filmstrip view mode, there is a 'Thumbnails' mode, which displays thumbnail
Thumbnail
Thumbnails are reduced-size versions of pictures, used to help in recognizing and organizing them, serving the same role for images as a normal text index does for words...
-sized images in the folder. A Folder containing images will also show thumbnails of four of the images from that folder overlaid on top of a large folder icon.
Web publishing
Web sites that offer image hosting services can be plugged into Windows Explorer, which the user can use to select images on their computer, and have them uploaded correctly without dealing with comparatively complex solutions involving FTP or web interfaces.Other changes
- Explorer gained the ability to understand the metadata of a number of types of files. For example, with images from a digital camera, the Exif information can be viewed, both in the Properties pages for the photo itself, as well as via optional additional Details View columns.
- A Tile view mode was added, which displays the file’s icon in a larger size (48 × 48), and places the file name, descriptive type, and additional information (typically the file size for data files, and the publisher name for applications) to the right.
- The Details view also presented an additional option called "Show in Groups" which allows the Explorer to separate its contents by headings based on the field which is used to sort the items.
- The toolbars can be locked to prevent them from accidentally being moved. This same capability was also added to the taskbar at the bottom of the screen, as well as to Internet Explorer’s toolbars.
- Windows Explorer also gained the ability to burn CDs and DVD-RAMDVD-RAMDVD-RAM is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.-Design:DVD-RAM is one of three competing...
discs in Windows XP. - If XP SP2 or 3 is upgraded to Internet Explorer 7Internet Explorer 7Windows Internet Explorer 7 is a web browser released by Microsoft in October 2006. Internet Explorer 7 is part of a long line of versions of Internet Explorer and was the first major update to the browser in more than 5 years...
or 8Internet Explorer 8Windows Internet Explorer 8 is a web browser developed by Microsoft in the Internet Explorer browser series. The browser was released on March 19, 2009 for Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, and Windows 7. Both 32-bit and 64-bit builds are available...
,explorer.exeno longer hosts Internet Explorer ActiveX controls with a view to render HTML files, it instead spawns off a newiexplore.exeprocess. - The sort order has changed compared to the one in Windows 2000. For file names containing numbers Windows Explorer now tries to sort based on numerical value rather than just comparing each number digit by digit for every character position in the file name.
Windows Vista and Windows Server 2008
Search, organizing & metadata
Windows Explorer includes significant changes from previous versions of Windows such as improved filtering, sorting, grouping and stacking. Combined with integrated desktop search, Windows Explorer allows users to find and organize their files in new ways, such as Stacks. The “Stacks” view groups files according to the criterion specified by the user. Stacks can be clicked to filter the files shown in Windows Explorer. There is also the ability to save searches as virtual folders or Search Folders. A Search Folder is simply an XML file, which stores the query in a form that can be used by the Windows search subsystem. When accessed, the search is executed, and the results are aggregated and presented as a virtual folder. When sorting items, the sort order no longer remains consistently Ascending or Descending. Each property has a preferred sort direction. For example, Sort by Date defaults to Descending order, as does Size. But Name and Type default to Ascending order.Windows Explorer also contains modifications in the visualization of files on a computer. A new addition to Windows Explorer in Vista and Server 2008 is the Details pane, which displays metadata and information relating to the currently selected file or folder. The Details pane will also display a thumbnail of the file or an icon of the filetype if the file does not contain visual information. Furthermore, different imagery is overlayed on thumbnails to give more information about the file, such as a picture frame around the thumbnail of an image file, or a filmstrip on a video file. Thumbnails can be zoomed on.
Layout and icons
Windows Explorer in Windows VistaWindows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...
and Windows Server 2008 also introduces a new layout. The Task Panes from Windows XP are replaced with a toolbar on top and a Navigation pane on the left. The Navigation pane contains commonly accessed folders and prepopulated Search folders. Seven different views are available to view files and folders, namely, List, Details, Small icons, Medium icons, Large icons, Extra large icons or Tiles. Automatic folder type discovery automatically detects the contents of a folder and display the correct detail settings. File and folder actions such as Cut, Copy, Paste, Undo, Redo, Delete, Rename and Properties are built into a dropdown menu which appears when the Organize button is clicked. It is also possible to change the layout of the Explorer window by using the Organize button. Users can select whether to display Classic Menus, a Search Pane, a Preview Pane, a Reading Pane, and/or the Navigation Pane. The Preview pane, allows for previewing files (viewing documents and playing media files) in addition to the Details pane. Also, Explorer can show a preview for any image format if the necessary codec for the format is installed in the Windows Imaging Component
Windows Imaging Component
The Windows Imaging Component is a Component Object Model based imaging codec framework introduced in Windows Vista and Windows XP Service Pack 3 for working with and processing digital images and image metadata...
.
The address bar has been replaced by a breadcrumbs
Breadcrumb (navigation)
Breadcrumbs or breadcrumb trail is a navigation aid used in user interfaces. It allows users to keep track of their locations within programs or documents. The term comes from the trail of breadcrumbs left by Hansel and Gretel in the popular fairytale....
bar for easier navigation. It shows the full path to the current location. Clicking any location in the path hierarchy takes the user to that level, instead of repeatedly pressing the Back button. This is similar to what is possible in Windows XP by pressing the small down-arrow next to “Back” and selecting any folder from a list of previously accessed folders. It is also possible to navigate to any subfolder of the current folder using the arrow to the right of the last item, or to click in the space to the right of this to copy or edit the path manually. As with many other Microsoft-made Windows Vista applications, the menu bar is hidden by default. Pressing the Alt key makes the menu bar appear.
Check boxes in Windows Explorer allow the selection of multiple files. Free and used space on all drives is shown in horizontal indicator bars. Icons of various sizes are supported – 16 x 16, 24 x 24, 32 x 32, 48 x 48, 64 x 64, 96 x 96, 128 x 128 and 256 x 256. Windows Explorer can zoom the icons in and out using a slider or by holding down the Ctrl key and using the mouse scrollwheel.
Other changes
With the release of Windows Vista & Server 2008 and Windows Internet Explorer 7Internet Explorer
Windows Internet Explorer is a series of graphical web browsers developed by Microsoft and included as part of the Microsoft Windows line of operating systems, starting in 1995. It was first released as part of the add-on package Plus! for Windows 95 that year...
for Windows XP, Internet Explorer is no longer integrated with Windows Explorer. Unlike older versions, Windows Explorer does not host Internet Explorer controls in its own process, rather it launches a new process when necessary. In Windows Vista and Server 2008 (and in Windows XP as well if IE7 or 8 is installed), Windows Explorer no longer displays web pages, and IE7 does not support use as a file manager, although one will separately launch the other as necessary.
When moving or copying files from one folder to another, if two files have the same name, an option is now available to rename the file; in previous versions of Windows, the user was prompted to choose either a replacement or cancel moving the file. Also, when renaming a file, Explorer only highlights the filename without selecting the extension. Renaming multiple files is quicker as pressing Tab automatically renames the existing file or folder and opens the file name text field for the next file for renaming. Shift+Tab allow renaming in the same manner upwards.
Support for burning data on DVDs (DVD±R, DVD±R DL, DVD±R RW) in addition to CDs and DVD-RAM
DVD-RAM
DVD-RAM is a disc specification presented in 1996 by the DVD Forum, which specifies rewritable DVD-RAM media and the appropriate DVD writers. DVD-RAM media have been used in computers as well as camcorders and personal video recorders since 1998.-Design:DVD-RAM is one of three competing...
using version 2.0 of the Image Mastering API
Image Mastering API
The Image Mastering Application Programming Interface, or IMAPI, is a component of Microsoft Windows operating system used for CD and DVD authoring and recording....
was added.
In case a file is in use by another application, Windows Explorer informs users to close the application and retry the file operation. Also, a new interface 'IFileIsInUse' is introduced into the API which developers can use to let other applications switch to the main window of the application that has the file open or simply close the file from the “File In Use” dialog. If the running application exposes these operations by means of the IFileInUse interface, Windows Explorer, upon encountering a locked file, allows the user to close the file or switch to the application from the dialog box itself.
Removed and changed features
The ability to customize the layout and buttons on the toolbars has been removed in Windows Vista’s Explorer, as has the ability to add a password to a zipZIP (file format)
Zip is a file format used for data compression and archiving. A zip file contains one or more files that have been compressed, to reduce file size, or stored as is...
file (compressed folder). The Toolbar button in Explorer to go up one folder from the current folder has been removed (the function still exists however, one can move up a folder by pressing Alt+↑). Although still fully available from the menus and keyboard shortcuts, toolbar buttons for Cut, Copy, Paste, Undo, Delete, Properties and some others are no longer available. The Menu Bar is also hidden by default, but is still available by pressing the Alt key, or changing its visibility in the layout options. Several other features are removed such as showing the size on the status bar without selecting items, storing metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
in NTFS secondary streams, the IColumnProvider interface which allowed addition of custom columns to Explorer and folder background customization using desktop.ini.
The option "Managing pairs of Web pages and folders" is also removed, and the user has no way of telling Vista that a .html file and the folder with the same name that was created when saving a complete web page from IE should be treated separately, that is, you cannot delete the folder without deleting the html file as well.
A solution to this is provided on (http://windowsxp.mvps.org/webpairs.htm). After the webpairs.reg file has been merged into the registry, the "Managing pairs of Web pages and folders" option is available in the Folder Options View tab.
The ability to right-click a folder and hit "Search" has been removed, as have the fields to fill in to customize your search. Now you must highlight the folder you wish to search and enter your keywords in the search field in the top right corner, however, you may not enter any other search parameters until after the system has finished searching the entire folder based on that one (or few) keywords. Only then will the "Advanced Search" button appear, allowing you to enter further search parameters. This situation can be bypassed. While in Windows Explorer, the F3 key is hit. This should bring up the "Advanced Search" box.
Windows 7 and Windows Server 2008 R2
Libraries
Windows Explorer in Windows 7 and Windows Server 2008 R2 supports Libraries, virtual folders described in a.library-ms file that aggregates content from various locations - including shared folders on networked systems if the shared folder has been indexed by the host system - and present them in a unified view. Searching in a library automatically federates the query to the remote systems, in addition to searching on the local system, so that files on the remote systems are also searched. Unlike search folders, Libraries are backed by a physical location which allows files to be saved in the Libraries. Such files are transparently saved in the backing physical folder. The default save location for a library may be configured by the user, as can the default view layout for each library. Libraries are generally stored in the Libraries special folder, which allows them to be displayed on the navigation pane.By default, a new user account in Windows 7 contains four libraries, for different file types: Documents, Music, Pictures, and Videos. They are configured to include the user's profile folders for these respective file types, as well as the computer's corresponding Public folders.
In addition to aggregating multiple storage locations, Libraries enable Arrangement Views and Search Filter Suggestions. Arrangement Views allow you to pivot your view of the library's contents based on metadata. For example, selecting the "By Month" view in the Pictures library will display photos in stacks, where each stack represents a month of photos based on the date they were taken. In the Music library, the "By Artist" view will display stacks of albums from the artists in your collection, and browsing into an artist stack will then display the relevant albums.
Search Filter Suggestions are a new feature of the Windows 7 and Windows Server 2008 R2 Explorer's search box. When the user clicks in the search box, a menu shows up below it showing recent searches as well as suggested Advanced Query Syntax filters that the user can type. When one is selected (or typed in manually), the menu will update to show the possible values to filter by for that property, and this list is based on the current location and other parts of the query already typed. For example, selecting the "tags" filter or typing "tags:" into the search box will display the list of possible tag values which will return search results.
Arrangement Views and Search Filter Suggestions are database-backed features which require that all locations in the Library be indexed by the Windows Search service. Local disk locations must be indexed by the local indexer, and Windows Explorer will automatically add locations to the indexing scope when they are included in a library. Remote locations can be indexed by the indexer on another Windows 7 and Windows Server 2008 R2 machine, on a Windows machine running Windows Search 4 (such as Windows Vista or Windows Home Server), or on another device that implements the MS-WSP remote query protocol.
Federated search
Windows Explorer also supports federating search to external data sources, such as custom databases or web services, that are exposed over the web and described via an OpenSearchOpenSearch
OpenSearch is a collection of technologies that allow publishing of search results in a format suitable for syndication and aggregation. It is a way for websites and search engines to publish search results in a standard and accessible format....
definition. The federated location description (called a Search Connector) is provided as a
.osdx file. Once installed, the data source becomes queryable directly from Windows Explorer. Windows Explorer features, such as previews and thumbnails, work with the results of a federated search as well.Other changes
- Windows 7 and Windows Server 2008 R2 supports showing icons in the context menu and creating cascaded context menus with static verbs in submenus using the RegistryWindows registryThe Windows Registry is a hierarchical database that stores configuration settings and options on Microsoft Windows operating systems. It contains settings for low-level operating system components as well as the applications running on the platform: the kernel, device drivers, services, SAM, user...
instead of a shell extension. - The search box in the Explorer window and the address bar can be resized.
- Certain folders in the navigation pane can be hidden to reduce clutter.
- Progress bars and overlay icons on an application's button on the taskbar.
- Content view which shows thumbnails and metadata.
- Buttons to toggle the preview pane and create a new folder.
Removed and changed features
Similar to Windows Vista, several features have been removed in Windows 7 from Windows Explorer such as the collapsible folder pane, overlay icon for shared items, remembering individual folder window sizes and positions, free disk space on the status bar, icons on the command bar, ability to disable Auto Arrange and Align to Grid, sort bar for other views except details view, ability to disable full row selection in details view, automatic horizontal scrolling and scrollbar in the navigation pane and maintaining selection when sorting from the Edit menu.Windows 8
On August 29 2011, Steven SinofskySteven Sinofsky
Steven Sinofsky has been the President of the Windows Division at Microsoft since September 2008, responsible for the development and marketing of Windows, Windows Live, and Internet Explorer.-Education:...
of Microsoft Corporation announced in a blog post that Windows Explorer for Windows 8 will use the ribbon UI used by most other Microsoft products.
Extensibility
Windows Explorer can be extended to support non-default functionality by means of Windows Shell Extensions, which are COMComponent Object Model
Component Object Model is a binary-interface standard for software componentry introduced by Microsoft in 1993. It is used to enable interprocess communication and dynamic object creation in a large range of programming languages...
objects that plug-in the extended functionality into Windows Explorer. Shell extensions can be in the form of shell extension handlers, toolbars or even namespace extensions that allow certain folders (or even non-filesystem objects such as the images scanned by a scanner) to be presented as a Special Folder
Special Folders
On Microsoft Windows, a special folder is a folder which is presented to the user through an interface as an abstract concept, instead of an absolute folder path...
. Windows Explorer up to Windows XP also allows metadata
Metadata
The term metadata is an ambiguous term which is used for two fundamentally different concepts . Although the expression "data about data" is often used, it does not apply to both in the same way. Structural metadata, the design and specification of data structures, cannot be about data, because at...
for files to be added as NTFS
NTFS
NTFS is the standard file system of Windows NT, including its later versions Windows 2000, Windows XP, Windows Server 2003, Windows Server 2008, Windows Vista, and Windows 7....
Alternate Data Streams, separate from the data stream for the file.
Shell extension handlers are queried by the shell beforehand for modifying the action the shell takes. They can be associated on a per-file type basis - where they will show up only when a particular action takes place on a particular file type - or on a global basis - which are always available. The shell supports the following extension handlers:
| Handler | Description | Can be implemented on | Required shell version |
|---|---|---|---|
| Context menu handler | Adds menu items to the context menu. It is called before the context menu is displayed. | Per-file type basis | Windows 95 Windows 95 Windows 95 is a consumer-oriented graphical user interface-based operating system. It was released on August 24, 1995 by Microsoft, and was a significant progression from the company's previous Windows products... and later |
| Drag-and-drop handler | Controls the action upon right-click drag and drop and modifies the context menu that appears. | Global basis | Windows 95 and later |
| Drop target handler | Controls the action after a data object is dragged and dropped over a drop target such as a file. | Per-file type basis | Windows 95 and later |
| Data object handler | Controls the action after a file is copied to the clipboard or dragged and dropped over a drop target. It can provide additional clipboard formats to the drop target. | Per-file type basis | Windows 95 and later |
| Icon handler | Assigns a custom icon to an individual file amongst a class of file types. It is called before file icons are displayed. | Per-file type basis | Windows 95 and later |
| Property sheet handler | Replaces or adds pages to the property sheet dialog box of an object. | Per-file type basis | Windows 95 and later |
| Copy hook handler | Allows running, modifying or denying the action when a user or application tries to copy, move, delete, or rename an object. | Not associated with a file type | Windows 95 and later |
| Search handler | Allows shell integration of a custom search engine. | Not associated with a file type | Windows 95 and later up to Windows XP |
| Infotip handler | Allows retrieving flags and infotip information for an item and displaying it inside a popup tooltip Tooltip The tooltip or infotip is a common graphical user interface element. It is used in conjunction with a cursor, usually a mouse pointer. The user hovers the cursor over an item, without clicking it, and a tooltip may appear—a small "hover box" with information about the item being hovered... upon mouse hover. |
Per-file type basis | Windows Desktop Update Windows Desktop Update Microsoft's Windows Desktop Update was an optional feature included with Internet Explorer 4 , which introduced several updated shell features to the Windows 95 and Windows NT 4.0 operating systems... and later |
| Thumbnail image handler | Provides for a thumbnail image to be generated and displayed along with its alpha type when a file is selected or the thumbnail view is activated. | Per-file type basis | Windows Desktop Update and later. Windows Vista introduced a newer IThumbnailProvider interface that also shows thumbnails in the Details pane. The older IExtractImage is still supported but not in the Details pane. |
| Disk Cleanup Disk Cleanup Disk Cleanup is a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files... handler |
Add a new entry to the Disk Cleanup Disk Cleanup Disk Cleanup is a computer maintenance utility included in Microsoft Windows designed to free up disk space on a computer's hard drive. The utility first searches and analyzes the hard drive for files that are no longer of any use, and then removes the unnecessary files... application and allows specifying additional disk locations or files to clean up. |
Per-folder basis | Windows 98 Windows 98 Windows 98 is a graphical operating system by Microsoft. It is the second major release in the Windows 9x line of operating systems. It was released to manufacturing on 15 May 1998 and to retail on 25 June 1998. Windows 98 is the successor to Windows 95. Like its predecessor, it is a hybrid... and later |
| Column handler | Allows creating and displaying custom columns in Windows Explorer Details view. It can be used to extend sorting and grouping. | Per-folder basis | Windows 2000 Windows 2000 Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15 December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the... , Windows Me Windows Me Windows Millennium Edition, or Windows Me , is a graphical operating system released on September 14, 2000 by Microsoft, and was the last operating system released in the Windows 9x series. Support for Windows Me ended on July 11, 2006.... , Windows XP Windows XP Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base... & Server 2003 Windows Server 2003 Windows Server 2003 is a server operating system produced by Microsoft, introduced on 24 April 2003. An updated version, Windows Server 2003 R2, was released to manufacturing on 6 December 2005... |
| Icon overlay handler | Allows displaying an overlay icon over a shell object (a file or folder icon). | Per-file type basis | Windows 2000 and later |
| Metadata handler | Allows viewing and modifying metadata stored in a file. It can be used to extend details view columns, infotips, property pages, sorting and grouping. | Per-file type basis | Windows 2000 and later |
| AutoPlay AutoPlay AutoPlay, a feature introduced in Windows XP, examines newly discovered removable media and devices and, based on content such as pictures, music or video files, launches an appropriate application to play or display the content. It is closely related to the AutoRun operating system feature... handler |
Examines newly discovered removable media and devices and, based on content such as pictures, music or video files, launches an appropriate application to play or display the content. | Per file type category. In Windows XP only, per-device and per file type category. | Windows XP and later |
| Property handler | Allows viewing and modifying system-defined and custom properties of a file. | Per-file type basis | Windows Vista Windows Vista Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs... and later, on Windows XP if Windows Search Windows Search Windows Search is an indexed desktop search platform released by Microsoft for the Windows operating system.... is installed. |
| Preview handler | Renders enhanced previews of items without launching the default application when a file is selected. It can also provide file type-specific navigation such a browsing a document, or seeking inside a media file. | Per-file type basis | Windows Vista and later |
Namespace extensions are used by Explorer to either display some data - which are not persisted as files - in a folder-like view or to present data in a way that is different from their organization on the file system. This feature can be exploited by a Relational File System like liquidFOLDERS or Tabbles , clones of the ill-fated Microsoft WinFS
WinFS
WinFS is the code name for a cancelled data storage and management system project based on relational databases, developed by Microsoft and first demonstrated in 2003 as an advanced storage subsystem for the Microsoft Windows operating system, designed for persistence and management of...
. Special Folders
Special Folders
On Microsoft Windows, a special folder is a folder which is presented to the user through an interface as an abstract concept, instead of an absolute folder path...
, such as My Computer and Network Places in Windows Explorer are implemented this way, as are Explorer views that let items in a mobile phone
Mobile phone
A mobile phone is a device which can make and receive telephone calls over a radio link whilst moving around a wide geographic area. It does so by connecting to a cellular network provided by a mobile network operator...
or digital camera
Digital camera
A digital camera is a camera that takes video or still photographs, or both, digitally by recording images via an electronic image sensor. It is the main device used in the field of digital photography...
be explored. Source-control system
Revision control
Revision control, also known as version control and source control , is the management of changes to documents, programs, and other information stored as computer files. It is most commonly used in software development, where a team of people may change the same files...
s that use Explorer to browse source repositories also use Namespace extensions to allow Explorer to browse the revisions. To implement a namespace extension, the
IPersistFolder, IShellView, IShellFolder, IShellBrowser and IOleWindow interfaces needs to be implemented and registered. The implementation needs to provide the logic for navigating the data store as well as describing the presentation. Windows Explorer will instantiate the COM objects as required.While Windows Explorer natively exposes the extensibility points as COM
Component Object Model
Component Object Model is a binary-interface standard for software componentry introduced by Microsoft in 1993. It is used to enable interprocess communication and dynamic object creation in a large range of programming languages...
interfaces, .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
can also be used to write extensions, using the COM Interop
COM Interop
COM Interop is a technology included in the .NET CLR that enables COM objects to interact with .NET objects, and vice versa.COM Interop aims to provide access to the existing COM components without requiring that the original component be modified. It tries to make the .NET types equivalent to the...
functionality of .NET Framework. While Microsoft itself makes available extensions - such as the Photo Info tool - which are authored using .NET Framework
.NET Framework
The .NET Framework is a software framework that runs primarily on Microsoft Windows. It includes a large library and supports several programming languages which allows language interoperability...
, they currently recommend against writing managed
Managed code
Managed code is a term coined by Microsoft to identify computer program code that requires and will only execute under the "management" of a Common Language Runtime virtual machine ....
shell extensions, as only one instance of the CLR
Common Language Runtime
The Common Language Runtime is the virtual machine component of Microsoft's .NET framework and is responsible for managing the execution of .NET programs. In a process known as just-in-time compilation, the CLR compiles the intermediate language code known as CIL into the machine instructions...
(prior to version 4.0) can be loaded per-process. This behavior would cause conflicts if multiple managed add-ins, targeting different versions of the CLR, are attempted to be run simultaneously.
Limitations
Even in Windows 7, Explorer uses the ANSI API calls, so it is limited to operating on paths that have less than 260 (MAX_PATH in windef.h) characters. The limitation applies to some operations like copying, moving or deleting files (to the recycle bin), but not to simply accessing files by double-click. Other Microsoft file tools, like RobocopyRobocopy
Robocopy, or "Robust File Copy", is a command-line directory replication command. It has been available as part of the Windows Resource Kit starting with Windows NT 4.0, and was introduced as a standard feature of Windows Vista, Windows 7 and Windows Server 2008...
, do not have this limitation.
External links
- Sullivan, Kent. “The Windows 95 User Interface: A Case Study in Usability Engineering”. © 1996 for Association for Computing Machinery, Inc. An article written by Kent Sullivan, a developer on the Windows 95 UI team, detailing the usability studies and development processes that led to the creation of the Windows 95 Explorer interface.
- How To Customize the Windows Explorer Views in Windows XP
- MSDN: Creating Shell Extension Handlers
- The Complete Idiot’s Guide to Writing Shell Extensions
- Namespace extensions - the undocumented Windows Shell
- InfoTip shell extension in Delphi