if your scanner is a canon, you install the drivers first and then connect the scanner to the pc's usb port. if yours is a canon remove the software, reboot after removing usb cable to the scanner and then re-install software and then reconnect the scanner.
have a look on your scanners software cd and it may have installation instructions on there. sorry i cant be of more help.
you dont need to go into the bios to set up a scanner unless its a parallel port on that passes through your printer but as you say, its usb.