so i just finished building my first computer. it started up and installed windows succesfully. however, i don't think my graphics card is working. I have a PowerColor Radeon HD 6870 but when I do the Windows Experience Index test thing it gives my graphics a rating of 1.0/7.9. And it doesnt seem to be registering my card. But I have my monitor hooked up to the VGA port on my graphics card and i get the picture and everything on my monitor so it has to at least be working, right? I have 2 PCI-Express cables hooked up to my graphics card from my power supply and the graphics card is firmly in place on the motherboard. what could be wrong and how can i fix it? thanks