Apparently this is a known bug in Windows XP, for which Microsoft has a supported fix. The necessary patch is included in Windows XP Service Pack 1, and also is now available on the Windows Update site under “Recommended Updates” for Win XP Professional, titled “Restarting Windows XP.”
Then you could also go to device manager and choose view and then select show hidden devices in system devices. I think there will be a disabled device...just enable it and try to shutdown ur pc.
