I have an HP Scanjet 6200C and I can't get it to work. I've installed it on 4 computers already, and on all 4, the computers will not detect the scanner. I've installed the drivers and everything, but each time I try to do that, the install program tells me to upgrade my USB interface. What is this? I've tried upgrading the USB interface, but all it does is freeze my mouse and crash my comp, on all 4 computers. Any suggestions? Maybe the scanner is shot.