Windows XP Shut Down it Automatic Reboots

One of the things that is quite different about Windows XP compared to Windows 9x (9x is shorthand for Windows 95, Windows 98, and Windows Me in all their various versions), is that one can control how it responds to certain critical errors—those that cause the infamous Blue Screen of Death (BSOD). In Windows XP, the default setting is for the computer to reboot automatically when a fatal error occurs. If that fatal error only occurs when you're shutting down, the system reboots automatically.
If you haven't changed any of the system failure settings, you should be able to see the error by looking in the Event Log. But a better long-term solution is to turn off the automatic reboot so you can actually see the error when it happens—chances are it will tell you enough about itself to let you troubleshoot further. To change the recovery settings to disable automatic rebooting:
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.