ho fatto come hai detto tu ma:

LILO version 22.2, Copyright (C) 1992-1998 Werner Almesberger
Development beyond version 21 Copyright (C) 1999-2001 John Coffman
Released 05-Feb-2002 and compiled at 20:57:26 on Apr 13 2002.
MAX_IMAGES = 27

Reading boot sector from /dev/hda
Merging with /boot/boot-menu.b
Boot image: /vmlinuz -> boot/vmlinuz-2.2.20-idepci
Added Linux *

Skipping /vmlinuz.old
Boot other: /dev/hda1, on /dev/hda, loader /boot/chain.b
Fatal: First sector of /dev/hda1 doesn't have a valid boot signature