It's an interesting problem, and I googled for a loong time for it.
I see that a lot of people have the same problem, but none has posted a solution for it.
I have 2 DVD drives, and both drives don't recognize DVD-R's.
When you insert a DVD-R, your drive transforms to a CD Drive, and you see a "CD Drive(E)" next to the disk's icon and a "DVD-R" just under the icon.
I booted from a clean DOS disk, and used OAKCDROM.SYS + MSCDEX.SYS
Now, I can see all the DVD-R's, but can't copy because DOS doesn't recognize 2+ GB HDDs.
I installed various NERO 6&7 versions. NERO recognizes only the disk label, and shows it as empty.
I tried ISOBUSTER, and ISOBUSTER sees the disk full with files.
I tried ULTRAISO, and ULTRAISO also sees the disk fully.
But windows does not.
I removed all the file filters like pfc.sys, pxhelp20.sys, elbycdfl.sys.
I tried changing udfs.sys to different versions.
But windows is insistent on not recognizing DVD-R's.
This is clearly a software problem, but many people suggest hardware solutions like cleaning, power calibration etc.
Does anybody have an idea what may be the culprit to this?