Are you comfortable taking the machine apart and playing with the hardware?
First thing I might try is to switch the cables going from your hard disk and CD-ROM.
If each one has a sperate cable, then put the cable going form the hard disk to the CD Rom, and the cable going from the CD Rom to the hard disk.
Then go into your bios and have it re-detect the drives, and then reboot.
If both are on one cable, it's slightly more complicated.
You basically want to temporarily make your CD-ROM the 'primary IDE' master, and if possible the harddrive the secondary IDE master with 2 cables.
If you only have 1 cable and 1 IDE slot, you may have to mess with jumpers and stuff, and if you not familar with this stuff, I would take it to your favorite 'computer friend' and ask them to do it for you.
If none of this works, I would try taking the CD-ROM from a known working machine and temporarily put it into your machine to boot from just to get past the install.
I have worked with CD-ROM's before where the 'Boot From CD-ROM' part is broken, but the rest of the CD-Rom seems to work just fine.
Hope this helps. Good Luck