Have you tried going into the device manager and looking for any yellow marked items? Something similar was seen with Vista as well with usb drives.
USB Drive Problems with Vista
Either right clicking to uninstall followed by a full restart or to have Windows perform an automatic search won't always work. A manual search by selecting the device from the list of devices will often see Windows install the correct generic driver where you end up with "Windows has successfully installed your new hardware" type message.