you have choosen to burn as a bootable cd.
DON*T, burn it as an image.
This is a common misstake for some reason, the ISO contains all needed info for booting... no bootoption needed whaen burning, it is NOT a data CD it is a image, the drDOS is a BAD sign, it means that the CD is using a floppyimage of drdos as the boot medium..
if you open the CD in Win you likely see the knoppix-XXXXXXX.iso file on it.