Do as Idontwantspam said. If everything looks normal, rather, if everything looks opposite to what Idontwantspam described above, then your USB ports might have somehow fried themselves (short circuited - it happened to me). In either case, try uninstalling the USB devices, disabling/re-enabling them in the BIOS, etc. If that doesn't work, you'll need to get yourself a PCI USB 2.0 card.