Several years I had this problem in one particular instance of Windows XP Professional - an extremely slow shutdown upon clicking on Shutdown button. For several minutes system would completely freeze, and then Shutdown/Restart dialog box would finally come up. What did I know about the problem. It was extremely annoying. It was persistent. And it was happening only on one instance of XP, so that excluded the possibility of a faulty hardware. It was so bad, that I came up with a workaround. I would open up a Task Manager and end one after another svchost.exe processes running under SYSTEM name. A counter and warning would appear saying that...
