Try this. Open regedit. Go to HKEY_Users\.Default\Control Panel\Desktop. Right click the key AutoEndTasks, Modify, change the 0 to a 1. In the same area, you can also modify HungAppTimeout and WaitToKillAppTimeout to 1000.
I had the same problem, so I'm going to try morph416's solution. Hopefully it works. I'm a little nervous using regedit though. I don't want to screw up my computer and not be able to fix it.