Windows 7 64 Bit Freeze

I am on a 640 GB western digital HDD running Windows 7 Professional.

The symptom is that the computer RANDOMLY - no pattern to the freezing whatsoever- freezes. During this time, whatever sound was playing will stutter for a while, the screen will remain frozen with the image that was last on it. Their is no keyboard response, numlock etc... or mouse response.

Upon restarting, the event log has no recollection of what caused the issue. I have checked,many, many times, over the course of 3 weeks now. The only error it contains is the one stating that the computer unexpectedly shut down. Nothing else is pertinent.

I have all the latest drivers, for everything, BIOS updates, etc... as well as windows updates.

On top of that, i have reformatted my computer, and the problem still persists, but here's the kicker:

On a secondary drive, running windows XP professional 64 bit, the computer works just fine, never freezes at all, so i doubt its any hardware component, i have left it on for days to test this, and it still functions properly.

Specs:

E8500 Intel processor, core 2 duo 3.16 Ghz

8 GB of RAM

Cross-fire setup: two ATI Radeon HD4850 series cards

All on a Gigabyte EP45-UD3P motherboard