My father was having trouble installing a Brother printer on his Dell XP SP2 machine. It ran the install disk upto the point where he needs to plug in the USB connection - then it waits forever. Very odd.
I took the printer and got it installed on a laptop. It didn't like the "included" software but the printer itself worked ok.
While that was happening I needed to move some files from my flash drive onto the Dell, but it wouldn't intall the drivers. I tried a different Flash drive - same thing. Then a USB hard drive, which it didn't even react to!
I found the driver, USBSTOR.SYS in the system32 folder, which is newer than the driver in the laptop. Never the less I tried to update it from a CD burned from the lap top. It greyed out the box when got to the appropriate folder. So I can't even do it manually.
Try this remove all pluged in USB hardware, turn of Computer, on a Laptop you need to take the battery out and also remove the Mains Plug. Then Press and hold the Start Button on the computer for 5 seconds. Now try what you tried before with power back on