Sometimes I get damn startup problems that I can never seem to figure out. I have two hard drives, win2k set up on the master drive and Slack 10 on the slave drive. LILO installed in the win2k mbr. Win2k always boots just fine, but Slack not so all the time.
What happens is when I choose Slack from LILO it says this...

Loading Linux.............
BIOS Data check successful

Right after that bam, black screen and no hard drive activity at all. The only way to recover is do a hard reboot with the reset button on my case. Sometimes I have to do this a couple of times before Slack actually starts. Any ideas?
The hard drive is fine because this only happens with Slack 10. When I have other windowz on this drive they all boot fine. DMESG shows no errors either.

With both lilo and grub, it doesn't matter if it's one HDD with two OS's, or two HDDs with one OS each. If the kernel line in the config line is stated incorrectly, you can't boot (I've done it to myself often enough to know that for a fact).

Post the contents of your lilo.conf. I suspect the problem is there.

I have made this error. I pointed grub to the /boot partition, instead of the / partition. Lilo works the same way. The kernel line in the bootloader config file needs to know the partition in which the compressed kernel image is located (and the name of the compressed image), AND the partition in which the root of the filesystem (/) is located, even if they are the same.

# LILO configuration file
# generated by 'liloconfig'
#
# Start LILO global section
boot = /dev/hda
message = /boot/boot_message.txt
prompt
timeout = 1200
# Override dangerous defaults that rewrite the partition table:
change-rules
reset
# VESA framebuffer console @ 1024x768x256
vga = 773
# Normal VGA console
# vga = normal
# VESA framebuffer console @ 1024x768x64k
# vga=791
# VESA framebuffer console @ 1024x768x32k
# vga=790
# VESA framebuffer console @ 1024x768x256
# vga=773
# VESA framebuffer console @ 800x600x64k
# vga=788
# VESA framebuffer console @ 800x600x32k
# vga=787
# VESA framebuffer console @ 800x600x256
# vga=771
# VESA framebuffer console @ 640x480x64k
# vga=785
# VESA framebuffer console @ 640x480x32k
# vga=784
# VESA framebuffer console @ 640x480x256
# vga=769
# End LILO global section
# Windows bootable partition config begins
other = /dev/hda1
label = Windows
table = /dev/hda
# Windows bootable partition config ends
# Linux bootable partition config begins
image = /boot/vmlinuz
root = /dev/hdb1
label = Linux
read-only
# Linux bootable partition config ends