This article was previously published under Q269378
Windows 95, Windows 98, Windows NT, Windows 2000, and Windows XP contain and support user profiles, and in many respects, they behave the same. However, there are some differences. These differences may prevent a Windows 95 or Windows 98 user profile from being used or transferred to a Windows NT 4.x or Windows 2000 user profile with the exception of Windows 95 and Windows 98 clients that have been upgraded to Windows 2000 Professional. In this case, their user profile are converted.
The following are the key differences in behavior of user profiles for each operating system group.
Windows 95 and 98
When you log on to a Windows 95 or Windows 98 computer, the user profile is copied from the user's home directory to the local machine. When you log off, the user profile is then copied back to the user's home directory. The home directory is set in the user's account on either a Windows NT 4.x Server or Windows 2000 Server, Advanced Server or Data Center. This path must be in the Universal Naming Convention (UNC) and must be created prior to the implementation. Other differences include:
No support for common groups.
No support for a centrally stored Default User Profile.
Different files for the registry portion of User Profiles. The User.dat file in the various Windows operating systems is not interchangeable with the Ntuser.dat file in Windows NT 4.x or Windows 2000 profiles, primarily because the registry, which is a key component of the User Profile, is incompatible between operating system versions.
Windows 95 and Windows 98 User Profiles can be stored on NetWare servers.
Windows NT, Windows 2000 and Windows XP
User profiles in Windows NT, Windows 2000 and Windows XP, for the most part, function the same. These operating systems support local, roaming and mandatory profiles. However, there are some differences.
Windows NT 4.x uses the %SystemRoot%\Profiles folder to store profiles.
In Windows 2000 and Windows XP, the Systemdrive\Documents and Settings folder is used. Computers that are upgraded from Windows NT 4.x to Windows 2000 or Windows XP will retain and use the %SystemRoot%\Profiles folder.
Windows NT 4.x handled duplicate down-level account names by adding the following to the username of the profile, where each subsequent logon with a different user of the same name would increment the suffix by one:
Windows 2000 and Windows XP handle duplicate down-level account names as well but in a slightly more intuitive manner. A suffix is placed on the username of the profile that is either the name of the domain, if the user account is a domain account, or the name of the computer, if the user account is a local user account. If, by chance, another user with the same name from the same domain or computer logs onto the machine, Windows 2000 or Windows XP adds a .000 suffix to the domain or computer name. If the action happens again, it then starts incrementing the .000 as well.
Windows NT 4.x profile merge algorithm was not a merge but rather an Xcopy with full synchronization support.
Roaming Profiles and Expected Logoff Merge Behavior for Windows 2000 and Windows XP
The default behavior for Roaming profiles Merge Behavior at user logoff is timestamp based, so any file or object in the client machines' cached copy of the profile that has a different timestamp from the corresponding file on the server; will be copied back to the target profile server location.
At a minimum, the registry (ntuser.dat) and the ntuser.ini file will be copied back since the act of logon/logoff does modify the time/date stamp of ntuser.dat as newer than the cached copy on the Profile Server. If Group Policies are also active, then the ntuser.pol file will be copied back also.