Nice spec ...
I would suggest, as you probably have two sticks of ram, to remove one stick & try again ... what make of ram, do you know ?
Repeat with the other stick if the PC random reboots.
If the PC BSOD still persists,
I would still not rule out bad ram, but try disconnect all non essential peripherals, including DVD drives and second HD
There is a problem with Realtek, on-board devices & Vista, though it's a slim chance of it causing a BSOD, you never can rule out anything in diagnosing the problem.
With that in mind, I would also disable, via the BIOS, any on-board non essential devices such as the games port.
You will need to do these one at a time to try to pinpoint the cause.
Good luck ... let us know.