Restoring old profiles
Change the registry entry that designates the profile folder for the user.
These are stored at HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
There is one key for each user account that has logged on at the computer. The value ProfileImagePath specifies what folder constitutes the profile for that user. Changing it so it points at the old (original) profile folder restores the "old" settings.
This is handy to know if you move user accounts from one domain to another (e.g. NT 4 Domain to Active Directory).
Bruce Sanderson MVP