If it was a LILO/MBR problem, the floppy should still boot the system... unless the LILO config on the floppy is incorrect as well.
You can try to boot into rescue mode with your installation media, or use a Tom's RBT disk. After that, you should be able to 'mknod' and mount the volumes to check it out.
Look at
http://www.kevin.joubert.com/linuxnotes/recovery.htm for more info on this process.
One thing you may want to try is to go through the rescue process so that you can edit /etc/lilo.conf
There is a line in there usually that says "linear". Change that to "lba32" and then run /sbin/lilo
Pay attention to the "chroot" instructions in that document I listed above.