DVD Drive missing in My computer

Problem: Optical drives suddenly disappears only trace is in Device manager exclamation mark next
                 to driver entry.
Reason: This is usually caused by incd or other software creating an invalid upper or lower filter entry.
Repair: Open Regedit by typing "regedit.exe" into run command on your start menu.
            Go to - "HKLM/currentcontrolset/control/class/{4D36E965-E325-11CE-BFC1-08002BE10318}"
                       OR (where the heading on right-side under class is dvd/cdrom-drive)
            Delete all keys on right that has to do with upperfilter and/or lowerfilter.
            Close Registry Editor
           Reinstall driver in Device manager or restart PC.
           Drives should be working ounce more.

Hope this helped ENJOY!!