How many USB ports do you have? Possible your Canon Fax/Copier/Scanner took control of a USB port and that port is now dedicated to ONLY the scanner/copier. On older PC's you had to designate "Port #1" or "Port #2" when installing printers and such. On newer PCs w/ multiple USB ports, it shouldn't matter, but who knows.
You have to have more than 1 USB, have you tried all of them?
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