My Combo Drive is not visible

Please read to the end before atempting this.
Is this XP or Vista. In Windows based computers some times the High and Low filters get messed up in the registry. If the drive is still good and you had not had any issues with it not reading disks then the filter settings may be your problem. Try this:

1) Close all open programs
2) Click on Start, Run, and type REGEDIT and press Enter
Note: Vista doesnt come with the run command as a choice so just type REGEDIT in the search bar above Start..
3) Click on the plus signs (+) next to the following folders to open them.

HKEY_LOCAL_MACHINE

SYSTEM
CurrentControlSet
Control
Class
{4D36E965-E325-11CE-BFC1-08002BE10318}
(looks like same file name for XP and Visat?)

4) This folder is the DVD/CD-ROM Drive Class Description in the registry. Look for any of the following names in the right hand column.

UpperFilters
LowerFilters
UpperFilters.bak
LowerFilters.bak

5) If you see any of the above keys, right-click on each of them and choose Delete
6) Close the Registry Editor
7) Reboot your computer
8) Click Start
9) Open My Computer and check to see if your CD or DVD drive shows now.
Open the device manager for your version of Windows and make sure the Rom Drive is showing and that it is not showing an exclamation mark. If you still do not see the Rom drive then your drive may be defective. Note: you migh have to reinstall some of your CD or DVD playing/burning software. Hope this helps... Dale