I Can't Fix Error Code 43 on my GTX 560 TI

i've recently been having issues with my asus gtx 560 ti graphics card. The card has worked fine up until the point where i reinstalled windows 7 on a separate hard drive from my usual one. I thought it was just the drivers but i uninstalled them all and reinstalled them all again and nothing. i even went so far as to reinstall windows and all the drivers on the current hard drive. the fans are spinning as usual both pci E plugs are plugged into it, both lights are flashing green like usual. the display works but i cant open any games because it says unable to load direct3d and different direct X errors and i cannot increase my screen resolution past 1600X1200 Pixels. normally i had it at my monitor's default which was 1680X1050. That's the first thing i noticed that was weird. When i try to install some NVIDIA drivers it says "The NVIDIA setup program could not locate any drivers that are compatable with your current hardware. Setup will now exit." I've never seen this before and that's why im confused about it because i dont know what i would do if it fried/broken does anyone have any suggestions on what i should do? it would be greaty appreciated. thanks. P.S: it never had any issues in game recently; and it never froze while i was playing games or anything. also i make sure it doesnt overheat because i monitor the temperature frequently and i even have a third fan hooked up to it just in case.