I have a problem :(

[cantputt04]

Well today, I'm doing my normal thing, and I go to play Guild Wars and my picture is all blocky and tiley. I was like "what is this" so I tried Counter Strike. That was the same way. Bad picture quality. So I asked my friend about it. He suggested I clean out my video card slot and RAM slots. Well I did. Lot of dust in the GPU fan. I reset everything, nothing changed. I updated my drivers. Still nothing changed. I re-installed Direct X, that didn't work either. The blockiness is ONLY in games. Everything else is fine. I don't know what happened... I use a 6600 GT in a PCI-E mother board if that helps. So, anyone know what's wrong?

[giantkoreandorq]

Have you tried lowering your advanced settings such as AA in the Display properties or in games? Also, how long have you had that GPU?

[cantputt04]

I've had it for about a year, and I've tried lowering and raising the resolution, turning things on and off, it doesn't help. As soon as the window comes up, everything is just blocky... It's horrible...

[cantputt04]

This just in. Whenever I open a file-sharing program, my whole screen goes into tile-mode. Does this mean it's my operating system?