Here is a detailed fix:
http://theonlinetutorials.com/how-to-resolve-windows-xp-temp-profile-problem.html
The gist of it is, one browses in ‘regedit’ to here:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows NT\CurrentVersion\ProfileList
and one will find that the GUID key for the profile, is suffixed ‘.bak’, and replaced. One needs to remove the replacement, rename the .bak removing the suffix, and restore the ‘state’ entry from ‘8100’ hex (which means temporary) to ‘100’ hex (normal).
If the profile itself is corrupt and the goal is to replace it altogether, just remove all of the keys with the username within, including the .BAK if it exists.