How many disks do you have? Where are the windows partitions
located ? Without these questions answered it's hard to give you an exact answer but the lilo.conf file _might_ look something along these lines:
...
other = /dev/hda2
label = winme
other = /dev/hdb1
label = wintwok
table = /dev/hdb
...
If you're not sure about what partitions you could try:
# fdisk -l /dev/hda
# fdisk -l /dev/hdb
Reading the lilo.conf man page doesn't hurt either
Regards
J.P
EDIT: Don't forget to run /sbin/lilo after you make any changes to the lilo.conf file.