Hello and how are you? Your CD DRIVE may not for the following purposes:
1)- If you were using ur CD DRIVE before you restart ur PC then it may possible that you CD DRIVE's power cable's conection is lose or that power cable is out oof work. Try to connect diff power cable.
2)- The above problem may also caused because of deffective Data Cable. Try to use ur CD DRIVE's Data cable with ur Hard Dive and see if it works.
3)- Before doing above things, restart ur PC and pres pause button on ur keyboard when you see first screen then put any CD in your CD DRIVE and see if it works.
OTHERWISE YOUR CD DRIVE MAY BE DEFFECTIVE
Take care of you and others and be happy.
Dur-E-Wahab