Some of the current images of Redhat (specifically RHEL) have both bootloaders installed on the system. This makes it somewhat annoying when you are doing kernel upgrades as you have to modify both loader config or take a gamble.
Therefore, if you wish to find out which bootloader is used on the system, you will need to su to root.
As root, you need to run either of these commands:
dd if=/dev/hda bs=512 count=1 2>&1 | grep GRUB
AND dd if=/dev/hda bs=512 count=1 2>&1 | grep LILO
If the bootloader is found then it will say: Binary file (standard input) matches and this indicates this is the bootloader your system will use on startup.
This command will work on any of the RedHat based systems.
*IF* you have grub installed, an even easier solution to find out what the actual bootloader is, is:
It will print out whether grub or lilo is in use. If it prints something else, you must have an extraordinary bootloader.
Once you made sure you use grub, I'd recommend removing lilo by issuing.