One of our users has Windows XP running on his laptop. For about a week now he has been unable to shut down or log off of his computer. Ctrl-Alt-Del is not functioning, so I can't see if an app is running. There is nothing in the event log for this. When you go to Start -> Logoff or Shutdown, everything appears to work up until you select OK for the Restart, Shutdown, Log off, etc. Then the screen just flickers for a second and nothing else happens. I even tried forcing a shutdown from the command prompt using "shutdown -s -f"; same deal. Any one got any ideas?