DVD's Missing From My Computer Code 39 Error

Hi

Windows XP SP3

Have tried the proceedure below to fix DVD's not showing in My Computer and Code 39 in device manager.
Only found Lower Filters entry in registry which I deleted as suggested. On restarting the PC problem remains.
Can anyone suggest further course of action?

*********** Proceedure****************************

If updating the driver does not resolve the problem, it indicates that there is a problem in the registry. To fix this problem, you may have to remove a few keys from the registry.

After you have removed the registry keys listed below, you will have to reinstall all applications that you use for CD or DVD recording to make them work properly.
To fix the error by editing the registry, perform the following steps:

1. Exit and close all applications currently running on your PC.
2. On Start > Run type Regedit and press the Enter key.
3. Next, navigate to the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\ Control\Class\ {4D36E965-E325-11CE-BFC1-08002BE10318}
4. Delete any of the following registry entries if they exist under this key:
o LowerFilters
o LowerFilters.bak
o UpperFilters
o UpperFilters.bak
5. Restart your PC and open My Computer to ensure that the CD-ROM drive is visible.
6. Also, open the Device Manager again to ensure that the yellow exclamation mark and the error code is now gone.
7. Restart your PC and open My Computer to ensure that the CD-ROM drive is visible.
8. Also, open the Device Manager again to ensure that the yellow exclamation mark and the error code is now gone.

**********************************************************************

 

Try this expanded version of what you did:

Copy the codet below. Open Notepad and paste it in. Save the result in a suitable location as drive.reg - making sure that the default .txt extension doesn't appear in the file name (Save as type = All Files).
Double-click on the saved .reg file to merge the contents.
Restart.

Code:

REGEDIT4

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318}]
"UpperFilters"=-
"LowerFilters"=-

[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdr4_2K]

[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdralw2k]

[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Cdudf]

[-HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UdfReadr]

 

Sorry for the delay in replying just had chance to try the suggestion.

Unfortunatly it didnt work.
Made the .reg file as suggested, double clicked, merged and restarted. Still showing yellow exclamation marks for DVDs in device manager.

Have I missed out some other steps?

I can't even do a complete re-install as the DVD drives are not working.
Any more ideas??