Special Folders

On Microsoft Windows operating systems, Special Folders are folders which are presented to the user through an interface as an abstract concept, instead of an absolute folder path. This makes it possible for an application to ask the operating system where an appropriate location for certain kinds of files can be found, regardless of what version or language of operating system is being used.

Overview

Windows uses the concept of special folders to help present the contents of the computer to the user in a fairly consistent way that frees the user from having to deal with absolute file paths, which can (and often do) change between operating system versions, and even individual installations. The idea has evolved over time, with new special folders being added in every version of Windows since their introduction in Windows 95.

Microsoft's "Designed for Windows" logo requirements [http://www.microsoft.com/whdc/winlogo/ Windows Logo Program] state that an application must make use of Special Folders locations to locate the appropriate folders in which documents and application settings should be stored.

A Special Folder can either be a reference to a physical file system directory, or a reference to a "virtual" folder. In the former case, they are analogous to environment variables — in fact, many of the environment variables that are set in a user's session are defined by where the special folders are set to point to.

Virtual folders, however, do not actually exist on the file system; they are instead presented through Windows Explorer as a tree of folders that the user can navigate. This is known as the Shell namespace. On Windows XP systems, the root of this namespace is the "Desktop" virtual folder, which contains the "My Documents", "My Computer", "My Network Places" ("Network Neighborhood" in Windows 95 and 98) and "Recycle Bin" virtual folders. Some virtual folders (like Desktop) have an accompanying special folder that is a reference to a directory on the physical file system. Windows Explorer displays the combined contents of a virtual folder and its associated file system folder to the user. This can be seen in Figure 1, which shows the Folder view in Windows XP's Explorer; in the Desktop virtual folder, the four standard virtual folders can be seen, as well as an additional folder, "a folder on the desktop", which is a real folder located in the Desktop directory in the user's profile.

Some third-party programs add their own virtual folders to Windows Explorer.

List of special folders

The following tables list most of the file system and virtual folders that are available as of Windows XP. The OS version in which each special folder was introduced is given as well.

File system directories

Notes:
# The "Desktop" "virtual folder" is not the same thing as the "Desktop" "special folder". The Desktop virtual folder is the root of the Windows Shell namespace, which contains other virtual folders. [ [http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/programmersguide/shell_basics/namespace.asp The Shell Namespace] ]
# "Local Application Data" differs from "Application Data" in that files located in the "Local" variant are also intended to be specific to the machine it is on. This only has relevance if the user's profile is a Roaming Profile in a Windows Server domain environment. [cite book
title = The Old New Thing
edition = 1st edition
chapter = Taxes
pages = pg. 451
last = Chen
first = Raymond
authorlink = Raymond Chen
year = 2006
publisher = Pearson Education
id = ISBN 0-321-44030-7]
# As with Desktop, the "My Documents" "virtual folder" differs from the "My Documents" "special folder". If the virtual folder variant is asked for, it will appear in a file dialog as a sub-directory of the "Desktop" virtual folder, instead of the user's profile directory as it physically exists on the hard drive.

Virtual folders

Notes:
# The "Desktop" "virtual folder" is not the same thing as the "Desktop" "special folder". The Desktop virtual folder is the root of the Windows Shell namespace, which contains other virtual folders. [ [http://msdn.microsoft.com/library/default.asp?url=/library/en-us/shellcc/platform/shell/programmersguide/shell_basics/namespace.asp The Shell Namespace] ]
# As with Desktop, the "My Documents" "virtual folder" differs from the "My Documents" "special folder". If the virtual folder variant is asked for, it will appear in a file dialog as a sub-directory of the "Desktop" virtual folder, instead of the user's profile directory as it physically exists on the hard drive.

See also

* Microsoft Windows
* Windows Explorer
* Tweak UI

References

External links

* [http://msdn.microsoft.com/en-us/library/cc144090(VS.85).aspx Shell Programmer's Guide - The Shell Namespace] — MSDN documentation on Shell namespaces
* [http://msdn2.microsoft.com/en-us/library/bb762494.aspx CSIDL Values] — MSDN documentation containing a complete list of all available special folders and virtual folders
* [http://www.microsoft.com/windowsxp/downloads/powertoys/xppowertoys.mspx Microsoft PowerToys for Windows XP] — TweakUI is available for download on this page
* [http://msdn.microsoft.com/en-us/library/system.environment.specialfolder.aspx Environment.SpecialFolder Enumeration] — MSDN documentation on accessing special folder values in the .NET Framework
* [http://www.nirsoft.net/utils/special_folders_view.html Utility that shows the path of all special folders]