Why can't I log off, restart, or shut down my Windows XP machine?

A. When you attempt to log off, restart, or shut down an XP system and you see a flash on the screen and nothing else, check whether Symantec Norton Antivirus 2003 is installed on your computer. If Norton Antivirus 2003 is installed, its ccApp.exe component causes the problem you describe. To solve the problem, use the Symantec LiveUpdate feature to download the updated Symantec Common Client programs. Installing these programs should fix the problem.

As a workaround on an XP Professional Edition machine in a workgroup or on an XP Home Edition computer, perform the following steps:

1. Click Start and select "Log Off."
2. Click Switch User.
3. Click Turn off .
4. Click Turn Off or Restart.
5. At the prompt that warns that other users are logged on to this computer and asks whether you want to continue, click Yes.