Yup, I'd installed all those drivers on previous installations, nothing worked. Also, seems as though everything is compatible. I've booted into safe mode and everything seems okay, thought I can't do too much to stress test it in safe mode. I've run stress tests on all the hardware, so it doesn't seem like it's that.
Also swapped out my GTX 560ti and replaced it with a GTX 560, the only thing that froze then was the keyboard (good old Logitech G15's lol). However, I put the 560 ti in my other system running Windows 8 and i7 860 and it lost power and crashed reasonably soon after putting it in. Did furmark testing on the video card, and it seemed to be fine though. Possibly a problem with Windows 8 and the GTX 560ti?
Perhaps I'll try putting Windows 7 on the other computer and see if it still crashes with the 560ti.