If you can't find such on your machine, then it's either disabled, the BIOS is out of date, the OS doesn't support your USB (Examples abound!) or other.
I cut my time loss by adding an USB PCI card.
More clues at http://www.usbman.com
After trying numerous times to connect my digital camera (olympus) to my computer to download photos...all I get are error messages that the usb for the camera can't be found. Olympus claims it's a microsoft problem...Microsoft claims it's a Dell problem. Dell doesn't know what my problem is. Anyone with any experience hooking a usb from camera to PC and actually getting it to work would be a great help.