Restore the missing userinit.exe file
Question : When I logon to either user account (both are set up as administrator) the password is accepted, the message “Loading settings” displays, the wallpaper shows briefly, then the message “Logging off” displays and it comes back to the welcome screen. I tried everything that is explained in this link. I do not see the file userinit.exe or wsaupdater.exe in the system32 folder.
Answer : The DllCache folder (c:\windows\system32\dllcache\) maintains a copy of userinit.exe. Simply copy it to the system32 folder. If not, you may have to expand a copy from the source. (either from the Windows XP CD, or from the ServicePackFiles source path)
As you’re unable to login to the system at present, either use Bart’s PE boot CD, or use the parallel Windows XP installation (if available) to carryout the file/registry operations.