About a year ago i built my computer and had no problems at all. Maybe 6 months ago i started having trouble with my games, i would start to play when all of a sudden the screen went to some weird screen with vertical lines of usually 2 colors going down the screen and whatever sound was being played in the game would loop and play over and over. Ive probably spent more time troubleshooting then actually playing games these last few months, im pretty sure ive tried everything. Things ive tried: Increasing the fan (not a temp problem) reinstalling graphics card overclocking in any and every way you could possibly think of cleaning all the dust out running torture tests (no errors) switching monitors check my power supply (its plenty enough) and a few other things For about the last month i havent had any issues at all but now all of a sudden the crashes are coming back. i havent changed anything or done anything different so im not sure why. Games it Happens to: CODMW2 , Mass Effect 2 , Borderlands. Games that work: Assassins creed , ETQW , FO3 , L4D2 I noticed that all of the games that dont work i got on steam, could this mean anything? but l4d2 was also purchased through steam but it works. System Specs: AMD Phenom 9950 Quad-Core Processor 2.60 GHz 8gb ram Windows Vista 64 bit ATI Radeon HD 4850 Im really confused and would really appreciate any help.