I'd like to start by thanking you for at least taking a look at my problem.
Since recently I have been getting BSOD's while playing Counter-Strike:Source (hl2.exe), it started completely random which is the odd part.
The first BSOD I had was an issue related to dxgmms1.sys - after that first one, plenty followed. All of them seemed to happen within 20 minutes of playing. I eventually formatted my harddisk and reinstalled Windows 7 Ultimate x64, hoping for a fix.
However, instead of a fix, I've been getting BSOD's (within 20 minutes of playing, again) on this fresh install. The only things installed on my computer, at this point in time, are my drivers
and Counter-Strike:Source since I wanted to see if it was caused by software.
I will run a memory test tonight and update you first thing tomorrow.