I have windows XP Home SP2. My computer used to just shut off automatically. EX: I click start, turn off computer, then click turn off. It would then start to shut down, saying logging off, saving your settings, windows is shutting down. Then my computer would turn off.
For a while now everytime I want to shut down or restart my computer, it will go through the shut down/restart process but it will hang at the screen that says windows is shutting down and I have to manually turn off my computer.
I can't figure out what is wrong.
Also I don't have an XP CD as my computer didn't come with one.

Check Event Viewer to see if errors are occuring at the time when you are shutting down the computer. To do this:

1. Shut down the computer and record the exact time when you do this. Let it sit on the "Shutting Down Windows" screen for at least 1 minute.
2. Restart your computer and open Event Viewer by clicking on Start, Run, and typing in eventvwr.
3. Check the Application and System section to see if there are any exclamation marks or red X's at the time that you shut the computer down. If you see any exclamation marks or X's, double-click on the item and copy it's description. Paste the description(s) in your reply.

ok, there were 2 things . . . .

Windows saved user Owner registry while an application or service was still using the registry during log off. The memory used by the user's registry has not been freed. The registry will be unloaded when it is no longer in use.

This is often caused by services running as a user account, try configuring the services to run in either the LocalService or NetworkService account.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

...

Faulting application aim.exe, version 5.9.3861.0, faulting module unknown, version 0.0.0.0, fault address 0x1221254f.

For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

Hi,

Try this: Click Start, click Run, type SERVICES.MSC, click OK. Stop the Automatic Updates service. Rename the c:\Windows\SoftwareDistribution folder to c:\Windows\SoftwareDistribution.old. Restart the Automatic Updates service.

it didn't work, those errors are still there when i run eventvwr and my computer still didnt shut down properly.

Did you maybe just add new USB devices to youre pc?

http://support.microsoft.com/?kbid=315664