Have you tried going into the device manager and remove all items related to USB such as Root Hub and USB controller, do this by right clicking each item and choosing uninstall ??
Once you have done that restart your pc & let windows find the usb items again, then try your usb flash drive. It should now install correctly & you should be able to use it again.
Incidentally when in device manager if you see anything with a yellow exclamation mark then remove that as well !!! It might be the usb flash drive after it had failed install & as such wont be redetected when plugged in !!!
If you right click on my computer, then go to properties & then to the hardware tab, you will see device manager here !!
Hope this helps,