Check the device manager to see if the device is working properly. If it is not, use the troubleshooting guide to figure it out.
If the device manager says it's working properly, make sure the drive is actually spinning the disk. The device manager will not ba able to tell you about a mechanical failure. I had the same problem a while back. The device manager said it was working fine but nothing would work. I finally realized the motor had went bad on the drive. After replacing the drive, all was well. Hope this helps.