When you upgrade your windows it will hose your MBR so you need to have a bootdisk for linux handy or just boot the Knoppix CD, chroot into your hdinstall and run lilo to get it back.
I used to have ntldr managing windows and lilo but it's a PITA. Every time you change lilo.conf you have to run lilo, make a new bootsector and copy it to C:\ instead of just running lilo.
Another drawback is that ntldr can't boot linux, so first you get the ntldr splash screen where you choose between windows and linux, and when (not if) you choose linux, you get the lilo splash screen where you choose linux again. Ok, so you can have really short timeouts but it's still a lot more convenient to just use lilo or grub.