Boot from a rescue disc of some sort....I like my gentoo disc for that.
at the bash prompt type the following
#grub
grub> root (hd0,0)
grub> setup (hd0)
grub> quit
What we have done here is...Specify where your /boot partition resides, Install GRUB in the MBR, and Exit the GRUB shell.
NOW... you have to edit your /boot/grub/grub.conf, so type the following.
# vi /boot/grub/grub.conf
# Which listing to boot as default. 0 is the first, 1 the second etc.
default 0
# How many seconds to wait before the default listing is booted.
timeout 5
# Nice, fat splash-image to spice things up

# Comment out if you don't have a graphics card installed
# splashimage=(hd0,0)/grub/splash.xpm.gz
title=Linux
# Partition where the kernel image (or operating system) is located
root (hd0,0)
kernel /kernelname root=/dev/hda3
I hope this helps a little, but, I thought SME used Lilo?
KegRaider.