GAMES freeze/crash PC to Black Screen

I first got SC2 at release and had issues with the game crashing. I followed some forum threads and managed to get it fixed (can't remember how). Recently I got the Walking Dead game, which crashed my computer just a few minutes into the game. After a few attempts I turned down the graphics and was able to play the game. Since then every time I've tried to play SC2 it has crashed. The screen locks up, changes to some funky colors and goes to a black screen. Have to force shut down and boot it back up. Since then I have updated drivers, disassembled my PC and cleaned everything out with compressed air, changed power supplies (both Antec 750Ws), added a 2nd hard drive from an older computer, formatted everything, reinstalled everything, updated all drivers again, downloaded Live Update 5 (from MSI website to update bios...had some terrible issues with that which I won't go into for now, but according to the updater the BIOS is up to date now). I use SlimDrivers to update all my drivers.

System Specs (from MSINFO32)
OS - Microsoft Windows 7 Home Premium (64 bit) Version 6.1.7600 Build 7600

Model - MS-7599

CPU - AMD Phenom(tm) II X4 810 Processor, 2600 MHz

RAM - 6GB DDR3

GPU - GeForce GTX 285 (1GB) Installed Drivers nvd3dumx.dll, nvwgf2umx.dll, nvwgf2umx.dll, nvd3dum, nvwgf2um, nvwgf2um


I'm truly at a loss right now because I've tried everything I know to do...Any help is appreciated! Thanks!!

I would suggest some hardware checks.

   Warning

Before you proceed with the following, answer these two questions: Are you still under warranty? Does your warranty allow you to open up the machine to check hardware? If you are unsure of the answers to these questions, contact your system manufacturer. :warn:WARNING: The steps that follow can void your warranty!!!

• If you are overclocking any hardware, please stop.
  
  
• Monitor temperatures during the following tests.
  
  Use the following programs to monitor the temperatures.​
  • Real Temp is a good CPU temperature monitor.
  • Speccy - System Information - Free Download will monitor all hardware temperatures.
  • HWiNFO, HWiNFO32 & HWiNFO64 - Hardware Information and Analysis Tools can be inaccurate for CPU temperatures, but is a good program for GPU temperature monitoring.
  • Use FurMark: VGA Stress Test, Graphics Card and GPU Stability Test, Burn-in Test, OpenGL Benchmark and GPU Temperature | oZone3D.Net to test the graphics card GPU. Let it run until the GPU temperatures even out or until the GPU temperatures reach a dangerous level (you can find the max temperature for your card on either the nVidia or AMD sites; if you are not sure, ask us). The goal is to get a steady temperature, find out if the GPU is overheating, or to see if there are any artifacts present in the test itself: look for strange pixelated patterns on the screen or colors that do not look like they belong. Then use the |MG| Video Memory Stress Test 1.7.116 Download to test your graphics card memory. Let the memory test run for at least seven passes; the more the better.
    
    
  • Run http://www.sevenforums.com/tutorials/100352-hardware-stress-test-prime95.html to determine any hardware problems. Run all three tests for a few hours each. If you get errors, stop the test and post back here.
    
    
  • Follow the steps for doing CPU stress test using IntelBurnTest
  
  
• Run the boot version of Memtest86+ paying close attention to Parts 2 and 3 of the tutorial. Also, in case Memtest86+ misses anything and comes up with no errors, run the extended version of the Windows Memory Diagnostics Tool for at least five passes. These you may want to run overnight since they take a long time to complete (run them an hour before bed each of the next two nights and check before going to sleep that they are still running).
  
  For Part 3: If You Have Errors: If you swap any memory components, follow these steps for ESD safety:
  1. Shut down and turn off your computer.
  2. Unplug all power supplies to the computer (AC Power then battery for laptops, AC power for desktops)
  3. Hold down the power button for 30 seconds to close the circuit and ensure all power drains from components.
  4. Make sure you are grounded by using proper grounding techniques, i.e. work on an anti-static workbench, anti-static desk, or an anti-static pad. Hold something metallic while touching it to the anti-static surface, or use an anti-static wristband to attach to the anti-static material while working.
  Once these steps have been followed, it is safe to remove and replace components within your computer.