I trying to access something in Windows Explorer today when it froze up. The computer didn't freeze, just Windows Explorer. So, naturally, I force quit it. Unfortunately, when you force quit Windows Explorer, it basically kills the entire windows interface. No task bar. No quick launch. No Start button. The Windows key becomes useless. It's like you're running Windows without windows.
I was about to restart the computer when my highly intelligent co-worker, Martin Olson, told me that you can restart your Windows Explorer. If you go into the task manager (CTRL+ALT+DELETE > Task Manager), go to the File menu. From there, select Run New and when prompted, enter "explorer". Suddenly, there was my Windows interface up and running again.