Kool. Analyzing the processes. Matter of fact, there is one other thing I'd like you to do.
Download and install STARTUP INSPECTOR for WINDOWS
. Let it do an analysis of your startup items, and remove all that are not needed.
Unless you have a single drive, with a single partition, and it's the same one you've bene formatting each time, then we can't rule out virus/spyware. Some of these buggers embedd themselves in your SYSTEM VOLUME INFORMATION folders on each partition of your drive, and then re-populate the main partition after a format. Granted, with no spyware/virus/firewall application running, and a fresh install, the only other things it could be are
By this I mean either the hardware is faulty - try alternate video card/memory/board. Or there is something on your machine that is hogging the resources when the graphics get intense, or sending so many packets in the background that you lag when in-game.
Try the card in a friend's machine and see how it works. If it gives the same trouble it's the card. If not, then we need to look at your memory/board as a possible problem.
Still waiting on your results and still analyzing the startup items and background programs.