You need to boot off the knoppix cd/dvd, mount the partition, chroot into the partition & then run grub-install. You may also need to edit the /boot/grub/menu.lst and /etc/fstab files.
See these forum thread for more info:
http://www.knoppix.net/forum/viewtopic.php?t=21927
http://www.knoppix.net/forum/viewtopic.php?t=19989
http://www.knoppix.net/forum/viewtopic.php?t=19389