No "Boot from CD" option in BIOS/Floppy Disk

[The Japanese Geek]

I have an old Dell Laptop with a modular bay (Battery, CD, and Floppy) There is no option of Booting From CD.
So, I tried to boot from the CDs.
When I try to boot KNOPPIX-Floppyu Disk, I get:

Kernal Panic - Not Syncing with : VFS: Unable to mount rootfs on Unkown Block (1,3)

Any Ideas?