Does it show up in Device Manager at all? If so, try uninstalling the drive and reboot to see if Windows will install the “new” hardware.
To see if the drive has a hardware failure of some sort, try booting the computer with a bootable disc in the drive. You’ll have to have the boot order set to look for the optical drive first (in the bios). Any type of bootable disc will work for this, like an operating system disc or something like the Ultimate Boot Disc: http://www.ultimatebootcd.com/
If you are certain that the boot order is set to look for the optical drive first, and it will not boot into the disc in the optical drive, you’ve got a defective drive.