|Are you logged on as Admin when this happens? If not, boot into Admin account, and see if you have the same problem. Also, boot into Safe Mode to see if Shutdown works from there. Let us know if the symptoms change...|
Can you logoff without shutting down? Can you restart with the Start button? If you can't logoff, and can't restart, check this link:
Check this one to see if you recognize the symptoms:
This link will explain how to use the Shutdown Event Tracker to help you analyze the problem:
This could help as well:
This might be helpful:
Does this seem familiar?:
I hate to bombard you with all those links, but WinXP can be difficult to troubleshoot when it comes to shutdown issues.
Good luck; let us know what you find after you check these links...