This is a problem mostly caused by malwares, but it may also happen if windows cannot find the userinit.exe. But there is a high probability that the malware renames the file or changes a registry entry that makes windows log off before logon.

The Solution :

• Boot using the windows xp cd into the recovery console mode.


• Then all you have to do is copy the userinit file from windows cd to the Drivelabel:/windows/system32 . for example if you have xp installed on c: drive then type this command in recovery console copy \Windows\ServicePackFiles\i386\userinit.exe c:\Windows\System32 .


• Now you will be able to login into windows.


• The problem in most cases is due to malware and for rectifying that after you login into the system do a system scan by using malware bytes . It's a freeware that will remove trojans or malwares. for more information about the software see this post .