Your boot floppy (mount it and open it) does not contain Lilo.

Assuming you want Lilo on the mbr of your primary master drive (C in Windows speak) which is where most people place it, just su to root and do:

/sbin/lilo

and it should work (you might like to post your /etc/lilo.conf here so that people can check it first). Do check that you have no boot sector blockers (crude anti-virus tools, often included in your bios) enabled as these will prevent /sbin/lilo from writing to your mbr.

Your boot floppy will still work (and you should keep it in a safe place).