Not detecting CD-R and CD-RW

I have two CD drives :- a teac CD-DVD, and a mitsumi CDRW. I am using Win98.
My problems started with an attempt to correct a conflict between my via
chipset and my alcatel broadband modem. I downloaded the latest drivers for
the mb, but when I tried to install, I got an error saying "registry error
please reboot"

After a couple of attempts I use norton system doctor to fix the registry.

Now my CD drives are not detected. They are not visible in my computer, nor
are there any references to them in device manager.

On startup I see that the bios sees them....

Help !!