If you find that your CD drive disappears all of a sudden, try this old but reliable fix.  Follow the 6 steps below and things should be back to normal:

1.  Click on the start menu.

2.  Go to Run and type “regedit” without the quotation marks.

3.  Maximize the HKLM and then go ahead and browse until you reach the key listed below.

HKEY_LOCAL_MACHINESYSTEMCurrentControlSetControlClass{4D36E965-E325-11 CE-BFC1-08002BE10318}

4.  In the right panel you’ll see something along the lines of “UpperFilter” and “LowerFilter” you want to click on each “filter” key and hit delete. Click yes when it asks to confirm if you wish to delete the key.

5.  Close Registry Editor

6.  Reboot your computer and the CD drive should be back.