You might try going into MSCONFIG and check to see what is running at not only start up but all the time. Sometimes you might even find it by using the CTRL-ALT Delete command and look in the Task Manager to see what is running in the background that might try starting while you're playing your games. If you use any of the IM clients check to make sure they're shut down. It's even possible you anti-virus software might be trying to do a scheduled scan if you didn't change it when you installed it.