I built this computer a little over a year ago and have never had any problems or errors. I first had an AMD GTX 460 graphics card but due to performance issues I installed a Radeon HD 7950 about a month ago. This is when the issues have started to occur. Durring start up the computer will freeze and nothing works, when I restart the computer everything turns on but the screen is black and the CPU fan doesn't turn on. Restarts occur whenever I am doing anything, running idle at 38C, browsing the web, playing youtube videos, playing video games (world of warcraft, League of Legends, Battle Field 3), within the first few minutes of start up or even hours of use. Any information would be greatly appreciated. Thank you
COMPUTER SPECS-
CPU: AMD Phenom II X2 555 3.20 GHz
Motherboard: ASUS M4A78T-E
RAM: 2x4GB, 2x2GB Total: 12GB
PSU: Corsair CX600 600w
GPU: Radeon Sapphire HD 7950 vapor-x 3GB
OS: Windows 7 Ultimate 64-Bit
COMPUTER SPECS-
CPU: AMD Phenom II X2 555 3.20 GHz
Motherboard: ASUS M4A78T-E
RAM: 2x4GB, 2x2GB Total: 12GB
PSU: Corsair CX600 600w
GPU: Radeon Sapphire HD 7950 vapor-x 3GB
OS: Windows 7 Ultimate 64-Bit