Windows XP Shut Down and Automatic Reboot Problems

Recovery Settings

1. Right-click My Computer, and then click Properties.

2. Click the Advanced tab.

3. Under Startup and Recovery, click Settings to open the Startup and Recovery dialog box.

4. Clear the Automatically restart check box, and click OK the necessary number of times.

5. Restart your computer for the settings to take effect.

Other mathod

1. Lauch Windows Task Manager.
2. End wgatray.exe process in Task Manager.
3. Restart Windows XP in Safe Mode.
4. Delete WgaTray.exe from c:\Windows\System32.
5. Delete WgaTray.exe from c:\Windows\System32\dllcache.
6. Lauch RegEdit.
7. Browse to the following location:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\
   Windows NT\CurrentVersion\Winlogon\Notify
8. Delete the folder ‘WgaLogon’ and all its contents

Reboot Windows XP.