Jammed START Button

[Maar]

Sometimes when I push the START button it stays jammed and I can't do anything with it. After restarting explorer.exe process I can use START button again.

[ckempston]

Corrupted Explorer maybe? Running "sfc /scannow" from the command line replaces Windows system files that have been changed or corrupted. I imagine reinstalling service pack will accomplish the same thing. I have also replaced explorer.exe with one from another computer with same patch level.