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'Windows Explorer' is an application that is part of modern versions of the Microsoft Windows operating system that runs on top of the Windows operating system and provides a graphical user interface for accessing the file systems, though is not integral to the running of a Windows computer. It is the component of the operating system that presents the user interface on the monitor and enables the user to control the computer. It is sometimes referred to as the Windows GUI shell, or simply "Explorer".

Contents

Overview

Evolution of Windows Explorer

Windows 95

Windows Desktop Update

Windows 2000 and Windows Me

Windows XP

Task Pane

Search companion

Image handling

Web publishing

Other changes

Windows Server 2003

Windows Vista

Search, organizing & metadata

Layout and icons

Other changes

Removed and changed features

Managed shell extentions

See also

Notes and references

External links

Overview

The Windows Explorer debuted in Windows 95 as a replacement for the older 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'' (which succeeded 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 extensions), and is responsible for displaying the desktop icons and wallpaper, the Start Menu, the task bar, and the Control Panel. Collectively, these features are known as the Windows Shell.

Evolution of Windows Explorer

Windows 95

Windows Explorer presents a browsing mode where each folder would open a new window showing its contents, in a spatial file manager fashion. Folder sizes and views are automatically set according to the contents of the newly opened folder. For example, a folder with two files opens with a smaller window than that of a folder with ten files. In addition, when there are hundreds of files in a folder, the folder would automatically display in "List" view. This browsing mode is reminiscent of the Program Manager of Windows 3.x.
Windows 95 was the closest Windows Explorer would come to being a spatial file manager in the same vein as the Macintosh Finder. In later versions of Windows Explorer, most of this functionality is disabled by default, favoring instead a "single-window" navigation design, a philosophy that later gained traction in Mac OS X.
Windows Explorer utilized ideas of the object-oriented user interface concept by providing every file object with an extensible context menu. The basic idea behind context menus was to give power users a more efficient and elegant way of executing file-related commands.

Windows Desktop Update

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 based on Internet Explorer technology, 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 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 Channels.

★ New virtual folders for Scheduled Tasks and Web Folders

Windows 2000 and Windows Me

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.
Sound and video files could be played right within the preview pane of Windows 2000 Explorer with its built-in media player. This feature of Explorer is unique to Windows 2000. Later versions of Windows would let user preview just the first frame of a video file, and no preview beyond displaying metadata for sound files.

Windows XP

Windows Explorer has undergone significant changes 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".

Task Pane

One immediately obvious change is the task pane, which is displayed on the left-hand side of the window instead of the traditional folder tree view. The task pane 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.
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

Windows XP's search capabilities were improved somewhat over previous versions of Windows, though in practice very little of its capability was used owing to a combination of privacy concerns and an interface that provoked varying degrees of dislike and ridicule. Microsoft introduced animated "Search Companions" in an attempt to make searching more engaging and friendly; the default character is a puppy named Rover, 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 Assistants, even incorporating "tricks" and sound effects.
The search capability itself is fairly similar to Windows 2000 and Windows Me, 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

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.

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 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-RAM discs in Windows XP.

Windows Server 2003

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.

Windows Vista

Windows Vista introduces a large number of changes to Windows Explorer.

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.
Windows Explorer also contains modifications in the visualization of files on a computer. A new addition to Windows Explorer in Vista 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 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. However, initially, users will be able to add metadata to only a few file types.^[1]

Layout and icons

Windows Explorer in Windows Vista also introduces a new layout. The Task Panes from Windows XP are replaced with a toolbar on top and a ''Favorites pane'' on the left. The ''Favorites 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. It is 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.

Other changes

Also, with the release of Windows Vista and Windows Internet Explorer 7 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 in Windows XP as well if IE7 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.
Windows Explorer can also now burn data on DVDs (DVD±R, DVD±R DL, DVD±R RW) in addition to CDs and DVD-RAM using IMAPI 2.0.
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. ^[2] 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 zip file (compressed folder). The Toolbar button in Explorer to go up one folder from the current folder has been removed. 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.

Managed shell extentions

Although more and more tutorials appear on programming shell extensions in .NET languages, and even Microsoft has provided some extensions written using the .NET framework such as the ''Photo Info tool'',^[3] they currently recommend against writing managed shell extensions, as only one instance of the CLR can be loaded per-process which would cause conflicts if multiple managed add-ins, targeting different versions of the CLR, are attempted to be run simultaneously.^[4][5]

See also

★ Comparison of file managers

Notes and references

1. Windows Vista Help: Add tags or other properties to files
2. 'File in Use' Demystified
3. .NET Shell extension from Microsoft - Photo Info tool
4. MSDN Mag
5. Don't do Shell Extension Handlers in .NET

External links

★ Sullivan, Kent. "The Windows® 95 User Interface: A Case Study in Usability Engineering". (C) 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

★ InfoTip shell extension in Delphi

★ Shell Extension City: A large collection of Windows shell extensions and related resources