Unfortunately there could be many different reasons why your computer will not shut down under XP. When your computer shuts down, devices, services, and programs are terminated but not before Windows attempts to save your systems' configuration and settings. During this process, is when you may encounter problems shutting down your system. Before seeking help for your problem, it would be wise to
. write down, or remember, anything new or recent, hardware or software installations, deleted or moved files, or any changes to the Windows enviroment ( i.e control panel ). http://support.microsoft.com/ is a vast resource, able to troubleshoot many different problems surrounding it's Windows XP Operating System.