We have a machine, Windows 7 (64-bit) with ASUS motherboard, in our building that only sometimes seems to go to sleep, but won't wake up. The machine is still running but shaking the mouse or hitting keys on the keyboard won't wake it up.

I have tried for days to isolate the problem, but every time we get to a "let's try this" scenario, it happens again, later.

All power options related to display being off are set to never, except the simple, "turn display off after..." setting. That is, the hard drive is set to never turn off, and the computer is set to never sleep nor hibernate.

All drivers seem to be up to date, but I am afraid I will hose the machine if I do a BIOS update (plus I figured that will probably have nothing to do with the issue and only make something else break).

Wasn't sure if there was something obvious I was missing?