I've had the machine to our computer guru who ran a check on all the hardware components for me, performed different tasks in IE and the Office Programs, and he said it never restarted or shut down by itself while in his shop.
I'm trying to see now if there's something else going on. I'm attaching a copy of the Hijack This log file. Thanks for your help - let me know if you need anything else.
Genoa School District