Did you install your motherboard's chipset drivers? If not, then there's your problem.
I'm not much with computers. I know enough that I get myself in trouble. Everything was working when I first installed windows 7 and eventually the USB ports foe my printer and then the others stopped working. I have not been able to use headphones on this computer for quite some time. It is a FRY'S tower with an assortment of hardware.
I went to the driver site and downloaded the Driver repair program by Parentologic and I ended up with some ATI something that made my icons and everything else smaller. Still no luck on the USB prots. What I get is a dialogue box that tells me "one usb attachment is not recognized..."