Wierd computer problem I'm having.

[nikimcbee]

I have Win 7 HE and a few days ago I had a 34 item Windows update. Now, my computer is really behaving strange.

So my computer will just shut off, like it's in sleep mode, but the fan is still running. There is no warning, it just turns off at random (3 times yesterday). So I turned it off last night and it was running this morning at the windows opening screen! WTF? How does a computer turn itself on? (not a joke)
I'm the only one that has access to this computer, so someone else didn't use it.

I ran a basic virus check. Nothing. I suspect it has something to do with the update. Anybody seen this before?

How the hell does a computer re-power itself on? I turned the thing off, not in sleep mode or re-boot. It was working just fine, prior to the update.