My son and I just built our first gaming computer. We used an I7 4770k, GeForce GTX770, 2x8GB Ram, Hydro cooled with a 750W power supply. We got the specs from a build your own gaming PC magazine. It worked great for 2 days but now he's getting lots of green dots moving across the screen when he games. The cables are not loose, we loaded the newest drivers, and the temperature is running cool. Can anyone help us? I'm out of my depth but willing to learn and any suggestions are appreciated.