you need to login as root and run lilo as root.
first, open Konsole (typically, the black screen with the shell thing on your taskbar)
This will give you a DOS-like window.
enter your root password; this should make the $ turn into a # at the cursor
now your new lilo is installed. If you see errors, correct them first in /etc/lilo.conf If everything looks good, reboot and see if that works. If something goes wildly wrong, you can use your install disks to reboot your system. As long as you don't format anything or redo partitions, you wont lose information on your drive, no matter how bad an error may seem. If you're new to linux, it wouldn't hurt to burn a knoppix disk just to be prepared while you're learning Linux. Knoppix runs off your cdrom drive, doesn't touch your harddrive, and is a great way to work with broken windows and Linux systems.