HP/Compaq :: Envy 15 G2 Hard Lockup/freezing During Gaming

Having an issue with my Envy. As soon as I got the machine I installed a SSD and clean copy of Win7. Drivers were downloaded from the thread in this forum section. The computer seems completely fine, temps are well within normal range (68c load CPU 74c load GPU). Besides the crashes, I have not experienced any other sort of instability with this machine.

The issue is an annoying hard lockup-my games will completely lock up and go into an infinite sound loop. The only remedy is a hard reset-I can not access the task manager or any other Windows functions. This happens at seemingly random, whether it be 5 minutes into a match or 2 hours in. The crash is not being triggered by heat-my system stays very cool, even during gaming.

The crashes seem to happen in any 3D game (but not furmark, for some reason)-at first I thought it was an issue with Bad Company 2, but after having time to muck around, I've realized that it is happening in all my games (including Just Cause 2, Team Fortress 2, GTAIV, Trackmania, Battlefield 2, etc).

I can't think of any reason why this is happening-I have a relatively clean Windows installation (need to save space on SSD) and up to date drivers. The only program I run in the background is NOD32, which has not given me any issues in the past with my other machines (I have tried disabling NOD32, to no avail).

My best guess is that it is video driver related. I have tried the Catalyst 10.4 driver from HPs website, as well as the 10.x ALL 8.74 beta driver-the 8.74 driver unlocks more resolution options and fixes BC2 load times, but both drivers are susceptible to the crash.