I'm not sure what "in windows i changed the hd volumeid" means, but lilo just goes looking for Windows on, say, hda1 (whatever's in /etc/lilo.conf). Lilo doesn't care what Windows thinks its "volumeid" is.

You didn't mess up lilo -- you messed up Windows. It wouldn't be booting now even if you'd never installed Knoppix and Knoppix had never installed lilo.

Try repairing Windows using the repair utilities on its installation CD. If you haven't made them yet, use other installation CD utilities to create Windows boot diskettes. Don't worry about dual booting until you get the Windows boot diskettes to start Windows. As soon as you're there, I'll bet that dual booting will be working again, too -- if not, edit lilo.conf (or install Knoppix once again!).