Knoppix live-cd ain't going to work if it doesn't boot from cd.

Can you enter the BIOS setup during the boot up process when the turn the machine on, you could perhaps be able to change the order in which it looks for devices to boot from and bring the cd to the top of the list...

If that doesn't work take a look at something like http://www.debian.org/distrib/floppyinst - that should do the trick!