I have a very strange situation with two computers I use. In my case, both computers attempt to shutdown but the shutdown process never completes. In this situation, the computer begins to shutdown and it goes through the shutdown process but after more than 30 minutes, the computer still does not shutdown and I have to manually shut the computer down by pressing and holding the power switch. In both cases I have not installed any software that would interfer with the shutdown process such as Nero (I did some research online but none of the suggestions helped). What could be causing this problem and what can I do about it (there are no specific error messages, just the shutdown message and the grayed out screen, but nothing else).