First, my specs:
Intel Core 2 Duo E8400
4GBs DDR2 800MHz RAM
The problem first started when I was playing Need For Speed Most Wanted. The game stuttered for a few seconds and then the textures went all blocky and stuff, but the game still ran smoothly. It hasn't happened since in that game, but now every time I play Half-Life 2 Episode 1 for a few minutes, without fail, it'll begin to stutter and then look like this:
The game will still run smoothly afterwards however (I'm getting 139 FPS in that picture).
I reinstalled my Nvidia drivers but that didn't help, and it's not overclocked and never has been, and I've never seen it go above 55C.
Any ideas? I really hope it isn't ****ed.