make sure all your drivers are installed. if you have a cd that came with your video card, make sure you install the drivers off that disc. if your trying to run SLI mode, make sure you have SLI activated in your motherboard bios. If you have an onboard chipset, make sure you have it disable in your bios, before using a PCI,AGP,PCIE card. one last thing, the system bios, can be accessed by pressing delete or f1 (this can vary) when you first turn on your computer. consult your manual before changing settings, beacuse u can really f**k up your computer. One last thing, if you cant find the drivers from a disc, get the drivers from the web. you new install also may be missing your motherboard drivers, so to check and see what your missing, go to start,control panel, SWITCH TO CLASSIC VIEW, system. then go to hardware,device manager. this will list all your comptuers hardware, and will let you see what needs to be installed.
Any questions, contact me at cessna310q@yahoo.com.
good luck!!