OK, maybe I can help here a bit.
First of all, I pray that you have some form of Linux rescue CD or floppy (eww) available. I think the first Slack CD would suffice as well.
Once you've booted the CD, there should be a /tmp
directory available. This dir is usually mapped into your RAM and is used as a temporary working space for files used in installation, for example.
One good thing about this dir is that it is the only writable dir on your temporary filesystem, therefore, you can use it to mount your "real" filesystems on your hard discs.
Assuming that you have a single / (root partition)
using some part of your hard disc (in this case i'll assume it's /dev/hda1)
, you'd merely need to mount it.
So do these steps:
mount /dev/hda1 slack/
At this point you should check to see if the partition is mounted properly. Just take a look at the /tmp/slack
directory, and traverse through some familiar dirs, such as your homedir for example.
If it is correct, then you should chroot to this dir:
Now, you should already be in your slack partition as if you actually booted into it.
I'd suggest you check your lilo.conf file and make sure the entries are correct. After that, just run /sbin/lilo
and try rebooting.
If it's a problem due to a kernel upgrade, you should now (at least) be able to boot up.
Hopefully this solves your problem.