For many chipsets (what is yours?) Intel gives no Usb 2.0 drivers. These are included in W2k sp4 and Xp sp2 and supposedly the more recent ones (what is your OS?).
By the way, I already had other Usb 2.0 chips on Pci extension cards, sold with drivers (typically from Orangeware), but the W2k sp4 drivers were better than the specialized ones.