You are a little shy of information here.
What make of computer, what specs?
Did this happen before you installed SP2?
Did the shutdown freeze before you tweaked it? If not what did it do?
What happens? What error messages do you get? What else is displayed on the screen?
Have you contacted the manufacturer?
Have you tried Microsoft's Knowledge Base?
Have you tried a Google search?
Try this web site. It may help;
I am running Win xp sp2. From the beginning I have been having trouble with shutdown. I have done many tweaks but about half the time it freezes at the end and I have to pull the plug when I want to start again.
Thanks in advance