So, based on your update, pick the laptop up, take it home and restore it to the original OS...THEN, if you continue having the problems, take it back.
If you don't have a copy of the original Vista 64 bit OS, I'm sure there are tons of copies floating around from the "Feedback Panel" giveaway a couple of years ago. I know I have 2 copies myself.
You did a clean install of the OS, not just install over the top of the old?
If so, it's probably a hardware problem.
Yep formatted the harddrive and did a fresh install.
Bummer. Try a different version of your video drivers? That's about all you can do.
If you have the extended warranty, brick the thing by doing a BIOS update and pull the battery out in the middle of the BIOS flash. Lets see them try to diagnose that.
Do it a couple of times until they agree to replace the laptop with an equivalent model or something that costs as much as you originally paid for it.
PS:
I hate Best Buy.
This.
Also, OP this sounds to me like it very well could be a software issue.