User profiles in Microsoft Windows
Microsoft Windows profile refers to the user profile that is used by the Microsoft Windows operating system to represent the characteristics of the user. Windows XP. Profile creation. Establishing a user account on the computer (or on its parent domain) does not create a profile for that user. The profile is created the first time the user interactively logs on at the computer. Logging on across a network to access shared folders does not create a profile. At first logon, a folder will typically be created under "Documents and Settings" (standard folder on English version  of Windows 2000, XP and Windows Server 2003) matching the logon name of the user. Should a folder of that name already exist, the profile-creation process will create a new one, typically named username.computername, on workgroup computers, or username.domainname on Active Directory member computers. Once a profile folder has been created, Windows will never automatically rename that folder. Thus if the username itself is subsequently changed, the profile folder will remain as is, and the profile will no longer match the username, which could lead to confusion. For this reason, the administrator might want to avoid renaming user accounts  if at all possible, or rename the folder manually and edit the registry to reflect the changes. The new profile is created by making a copy of a special profile named Default User. It is permissible to modify this Default User profile (within certain guidelines) so as to provide a customized working environment for each new user. Modification of the Default User profile should ideally be done prior to any users logging-on to the computer. If a user has already logged on once or more, the Default Profile has no effect whatsoever for that user. Profile contents. Note Some  of these subfolders are hidden from the users view in Windows Explorer. To see them you must uncheck "Hide System Folders" in the folder options. Special profiles. "Default User" - Plays a role in the profile-creation process, see above. "All Users" - This profile is present mainly to answer an issue related to software installation. It provides a way for setup programs to create desktop or start-menu shortcuts which will be visible to all users of the computer, not just the user running the setup program. The Application Data section may also contain program-data common to all users. "All  Users" acts purely as an information-store, it is never loaded as an active profile. "Administrator" - All versions of NT-based Windows have an administrator account and corresponding profile, although on XP this account may only be visible on the logon screen if the computer is started in safe mode. In Windows Vista, it is disabled by default. History and origin. Historically, the Windows 95-98 product line did not employ user-profiling as standard, with all users sharing the same settings, although that feature could be activated in Control Panel. The user-profiling scheme in force today owes its  origins to Windows NT, which stored its profiles within the system folder itself, typically under C:\WINNT\Profiles\. Windows 2000 saw the change to a separate "Documents and Settings" folder for profiles, and in this respect is virtually identical to Windows XP and Windows Server 2003. Recent developments. Windows Vista's profiles are functionally similar to those of Windows XP, but with some differences. Perhaps the key difference is that they are stored in a "C:\Users" folder, instead of "C:\Documents and Settings." Therefore, to cater for programs which are not Vista-ready, a symbolic link is also provided under the name of  Documents and Settings which invisibly redirects any attempted access of the latter to "C:\Users." The fact that the profile root folder appears twice in any folder listing has adverse implications for any backup program. Backup software needs to be aware of this Vista idiosyncrasy, or else it is possible to double the size of the backup by copying what appear to be two separate folders, both potentially containing the bulk of the data on the computer. A second change in Vista is that the media-specific "My Pictures" and "My Music" folders are now outside of the "My Documents" folder , instead of being subfolders (as well as removing the "My" Prefix - so My Documents becomes Documents, for example).