For those of you who are having problems with OTI-91X (mine is a OEM installed drive on a old Pentium II Packard Bell) and see messages that say "Device driver not found 'MSCD0001'", you may be needing the CDMKE.SYS driver file. I've set up the following so that you have a bootable floppy disk which allows you to access your CD-Rom drive
1. Format a floppy diskette on another Windows PC with "Copy System Files" check-box checked so that floppy is bootable.
2. Unzip the files in the downloadable CDMKE.ZIP file to the newly formated floppy diskette.
3. Reboot with the new floppy diskkette in the problematic PC.