That could be a symptom of a malicious infection; post a HijackThis log in our Viruses, Spyware, and other Nasties forum if you would like us to check that out.
Also- open the Event Viewer utility in your Administrative Tools control panel. Look through the System and Application logs to see if there are any error or warning messages which might shed more light on the cause.
We ask that members not tag their questions on to a thread previously started by another member (regardless of how similar your problem might seem). Not only does it divert the focus of the thread away from the original poster's problem, but it also makes it less likely that you yourself will get the individual attention that you need.
Please start your own thread and post your question there. When you do, please give us as much specific info as possible regarding the problem (exact error messages, system specs, troubleshooting steps you've already tried, etc.).
For a full description of our posting guidelines and general rules of conduct, please see this page: