Tell us the nature of your USB problem in the comments section,
someone may be able to help.
I have an anecdote of a USB hardware conflict error between a USB device( a printer) and another USB device a VOIP(voice over internet phone) specifically a magicJack.  It maybe of use if not post your problem in the comments section.
REPAIRING Device: magicJack Not Plugged In Error
Created my first web site in February'09 when I saw that no one else had a fix even mJack themselves for WindowsXP based mJacks.

One time I repaired the hardware conflicts by going into Start menu then Control Panel > System > Hardware > Device Manager. I went down to Universal Serial Bus controllers.
Then clicked the plus sign. The magicJack is listed as a USB composite device - I right clicked on it then clicked Properties.  It says Internet phone by TigerJet. Then > OK and clicked USB composite device again then right clicked then uninstall. Then plugged it into a different USB slot that worked. Also uninstalling Devices that were causing conflict also helped.
The device I was having problems with was my printer, I had it plugged into the USB slot next to magicJack. I have four USB slots on my computer, two on the back and two on the front. The magicJack is plugged into a rear slot so now I only plug my printer into the front slots and had not had problems for several months until I tried to plug my printer in again once next to the magicJack.

Some people claim USB hubs help. Have not tried that yet myself. What works for me is not to plug anything adjacent to the magicJack USB composite device.