Try these:
1. Boot the computer using your WinXP CD.
2. Press r to enter the Recovery Console when required.
3. At the command prompt type:
cd system32
4. Then type:
copy userinit.exe wsaupdater.exe
5. Then type:
exit
Reboot normally. You should now be able to logon. But you're not done
yet.
6. Run regedit (start>run>regedit)
7. Locate the "Userinit" key in:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows
NT\CurrentVersion\Winlogon\
8. modify the entry:
C:\WINDOWS\System32\wsaupdater.exe,
so that it reads:
C:\WINDOWS\System32\userinit.exe,
Note: Make sure the comma (,) is included at the end of userinit.exe
Also see this link:
Windows XP Auto Logs Off
http://www.paulscomputerservice.net/index.php?body=./os/autoLogoff.php
