Post 6,7,10,11, 15, and 19 are all off topic.
On a hardware level, I only suspect the GPU or Mobo.
To make sure its not a software conflict I'd reinstall with only the audio, cpu, gpu, and ethernet drivers. Not even any other software really. And then try to run a game, say an old game that used to run fine. This is of course only if you had the time.