Seriously, you have to reset it in the bios. You have to go to the section on monitoring for case being opened and set that to ignore. Reboot once into the OS. Then reboot, going back into the bios, and then resetting it to monitor the case being open again (that is, if you want it to).
Oh, and please don't ask me how to get rid of that applet about not being shut down properly. I had to delete that from the registry to shut that off. The PC came that way.