Running the ga-g41m-combo board with 8 gb ddr3 RAM , stock 2.7 GHz processor had a nvdia gts 450 and it was working perfectly , got a Radeon HD 6870 from a friend , got the extra power adapter for the GPU installed the drivers for win 7 ultimate 64bit but nothing will detect the GPU and it is/was working fine before i put it in my pc