Windows XP Log in / log off loop 

Cause :- Wsaupdater.exe is spyware that changes Userinit.exe, to Wsaupdater.exe in the registry

Resolution :- Use Recovery Console to copy Userinit.exe to Wsaupdater.exe

1. At the Recovery Console command prompt, type cd system32, and then press ENTER.

2. Type copy userinit.exe wsaupdater.exe, and then press ENTER.

3. Type exit, and then press ENTER

Modify the registry

1. Click Start, click Run, type regedit, and then click OK.

2. In Registry Editor, expand

HKEY_LOCAL_MACHINE  >>  SOFTWARE  >>  Microsoft  >>  Windows NT  >>  CurrentVersion  >>  Winlogon.

3. In the right pane, right-click userinit, and then click Modify.

4. Replace wsaupdater.exe with userinit.exe, (make sure to include the comma, as shown), and then click OK.

5. Restart your computer.

Delete the Wsaupdater.exe file

1. Log on to the computer by using an account that has administrator-level permissions.

2. Click Start, click Run, type%Windir%\system32, and then click OK.

3. Right-click wsaupdater.exe, click Delete, and then click OK.