SYSTEM SPECS: AMD Athlon 64 4200+ ATI Radeon 4850 1.5GB of Ram 120GB Hard Drive So here is my story! I sell my computer to a friend that then gives it to his nephew. His nephew trys playing Fallout 3 on it but when he gets 3 levels in the computers shut down. The games does not freeze/cash, the actual computer shuts down. He brings it back to me and is like do whatever you can. I instantly (being stupid) assume the processor is overheating so I add a Freezer 64 Pro to it and replace the old 120mm fan that was old with a new one. Let's do this damn thing! Starts the game up again and starts playing it again then BLAM! The computer shuts down again... *scratches my head* I now download Speedfan to check my temperatures on everything and low and behold my graphics card was hitting 78 degrees C and then shutting down! Got it! Replace the 8600GT with an ATI Radeon 4850. Install it and start playing the game... Yeah... It happens again... WTF! I posted on the Fallout 3 forums and asked them what they think... 3 replies all say that it is the power supply! So, after almost crying in the inside I go and buy a 650W Antec Earthwatts power supply! Install this bad boy and everything is running smooth (well can't really tell but whatever lol)! Go to play his game, then BAM! Computer shuts down again. What is next?! Ram?! Hard Drive?! I am running out of things to replace here! lol Any questions/comments would be greatly appreciated!