Suddenly My Windows XP Log In Then Log Off

Sign and Symptom

After we click the user account , It starts logging and the message (loading personal settings) starts, but suddenly during logging in it log's OFF and the message (Saving your personal settings) and goes back to the main screen with the three users icons. In Save Mode also the same things , you cannot do anything to log in into your account.

Diagnosis
Missing file or changing of the value Userinit key

Solution

A.Userinit-Missing

1.Boot into Full Support NTFS DOS
2.Check Userinit from c:\windows\systems32
3.If the file missing , copy from the other computer
4.Reboot

B.Editing Registry

1.Get Offline Registry Editor from http://home.eunet.no/~pnordahl/ntpasswd/
2.Get the Bootable CD - Using any software burn into the CD
3.Boot the CD
4.Load the 'software' registry
5.go to the full registry editor
6.Search for Microsoft/Windows NT/CurrentVersion/Winlogon key
7.Look the value of the Userinit subkey.
If it's not "C:\WINDOWS\System32\userinit.exe,", then change it.
8.Quit and save
9.Reboot
C. If got a large and partition hardisk.
1. Install another windows xp in the other partition
2. copy an userinit from windows/systems32(this from new OS)
3.then paste to the old windows XP