My Cd write always appears at startup, sometimes appears in XP but more often not. When it does appear in XP it will not write to a disk. It states there is no writable disk in the drive. It will read a disk. I have tried the removal of the upper value a prescribed by MS and also the reinstating of the install condition using the scannow command neither work.

You might want to consider the possiblity that the cd writer is bad or misconfigured. Double check your ide configuration or test the writer in a different machine.

Remove the Upperfilters and Lowerfilters values completely from the following registry key: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Class\{4D36E965-E325-11CE-BFC1-08002BE10318} Make a backup of your registry, then just navigate to the registry key above as you would in explorer. Once you get there... highlight the folder with the long number and you'll see "values" in the window on the right. Delete any that say "upperfilters" or "lowerfilters". You will see subfolders, don't mess with them. I don't think you need to reboot... just re-open explorer.