Not sure of your problem as the drive doesn't need to be installed as Windows will see it as an optical drive. Try booting the laptop with the optical drive already connected to the USB port. Does Windows now see it as a drive? If it doesn't work - shutdown, remove the drive from USB then reboot. Wait for Windows to settle on the desktop and then connect the drive. See if Windows picks it up then.
Is this a Powered DVD drive or does it get its power from the USB port?