Originally Posted by laitcg
Windows install may reset the bootable partition and mbr. Make sure your MBR is clean (from linux boot cd: dd if=/dev/zero of=/dev/hda1 bs=446 count=1) and use a partition manager to reset your boot partition to your lilo/grub partition.
that would just zero out the boot record of the first partition, not the MBR. hda1. the master boot record would be at the beginning of hda. I think doing this will just make things worse. If hda1 is a linux partition, you could mess up something there. If it's a windows partition, you could mess up something there.
You should be able to boot from a rescue cd and reinstall lilo from there.