Trouble booting 5.0 on dell 2100 w/win2000

I am trying to save files from this dell for a user. Have done all possible and I am now trying to use Knoppix 5.0 disc. The disc works on various machines, however, when I try to use it on the machine in question it won't boot. Here is what I have done, I went into the bios and disabled everything except the CDROM drive. It bypasses the drive and give error message "Invalid boot media in drive A". I can use the 2000 repair drive cd just fine. I am doing a scandisk repair right now.
How can I get the Knoppix to boot so I can recover the data files and reinstall the OS?

Lots of information about why your disc might not boot in this system including tips on using SBM to help boot it in Answer #1.

I didn't resolve the Knoppix booting issue but the Windows MBR was corrupt. After finding the 2000 OS disk,I rebooted and repaired using FIXMBR. Machine booted right back up fine and is running fine. Next week I may see if Knoppix will now start on the machine.