Motherboard is P35C-DS3R.
Graphics card was a 8800GT (now some cheap PCI express radeon)
Can't remember what the processor is, Core 2 Quad, Q9450 I believe (having seen the bios post many times!)
RAM 4GB, no idea, other than matched pair from OC. Was going to try taking a stick out and running with one (or the other) and see if I still get problems.
On a side note, I have specifically resisted the urge to put on *any* of my own drivers on this machine, just to discount that theory!
I would check your motherboard voltages out.
I used to have random bluescreen problems with my machine, was using a matched pair of OCZ, and to get rid of them I had to increase my RAM voltage from the default 2.4 to 2.7. Though when I upgraded my PSU, the issue went away because it was delivering much more stable voltage.
What size PSU are you running,and how many hard drives and other various peripherals are plugged in (especially bus powered USB devices)?
EDIT: The initial problem with mine looked like a graphics driver issue, as when I did get the bluescreen it was only ever when I was playing graphically intensive games. It turned out that it was when the graphics card went into 3d mode it just happened to pull more power, and dropped the voltage across the 5v rail and the RAM would drop out and crash the machine. Interestingly, XP would just freeze and not come back, while vista would bluescreen.