CD Rom does'nt recognise CD's

Machine,,,,,
HP,,XP,,2Ghz,,P4,,60Ghd,,1G DDR Ram.
Work puter, never on web, so very little protection !
Aquired a bug,, so reformatted ! Had Nero 5 installed !
Did'nt uninstall nero before reformat and have been told
that's the problem .
The CD Rom will not recognise a burnt CD, but indicates as
blank !!!
Was told to delete key values in registery on "upper/lower"
filters, but none of my machines have "Upper",,only "Lower"
filters, have deteted key values on these, reboot, same
values come back... Another HP I have indicates different
values,, much simpler,, another mach,, different but simpler !!
The values indicated are as follows,,,,
-
"drvmcdb sscdbhk5 PxHelp20 AFS2K MXL W2K Pfc" (Lower Filter)
-
My other HP only reads,,"MxlW2k"
I've deleted values, uninstalled CD Rom, reboot, still the same !!
Anyone ever face this problem before ?
Any assistance or clues would be GREATLY appreciated here !
I've seen some amazing solutions come from here, so I thought
there may be a cure for mine !! Here's Hoping !!
Thank You,,,
-
wfnk