WinME can't read CD filesystem; DVDs are OK

I friend has asked me to look at her computer. This WinME system has 2
optical drives, a Sony CRX100E CD-RW and a Hitachi GB-2500 DVD-ROM. Neither
drive can read CDs placed in them.

This is not a hardware problem. Both drives are fully accessible in Linux
(Knoppix live CD) and the 1st optical drive can be booted from in DOS. Both
drives are correctly identified as being present in the BIOS.

Each drive is given a drive letter in WinME and correctly identified. Each
drive can correctly determine in WinME whether there is a disk present in
the drive or not. In WinME, any given disk in either drive will show as
having zero bytes used with ~650MB available, and with a filesystem type of
"CDBLANK".

I removed both drives in Safe Mode and they were correctly redetected.
There is no indication of error (yellow exclamation mark, etc.) anywhere.

I just had a brainstorm and tried a DVD in the DVD-ROM drive. It works
correctly! So it appears that this WinME system simply cannot read the
ISO9660 filesystem.

I have an old version of "Easy CD Creator" (formerly by Adaptec). It
includes the "CD Copier" utility. Using this utility, I can copy a CD from
one drive (the DVD-ROM) to a disk in the other (the CD-RW).

The drives actually work. It is just that WinME can't read a filesystem from
either of them. More specifically it can't read a CD filesytem, since DVDs
read OK.

I installed the latest (late 2002) ASPI drivers from Adaptec. No difference
in behavior.

I'm guessing that some crucial system file was lost in a prior virus
cleaning. Any advice on how to restore the ability of WinME to read a CD
filesystem?

Thanks.

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