Duncan,

Grub on MBR should work.  Config file is menu.lst usually located in hdx/boot/grub.
Just edit file to add options.  Note that grub counts partitions from zero.

Mine resides on MBR, triple boots Win2K, Win95 and RH.  Here is my menu.lst, edit 
as needed for your system:

***

# This is the amount grub waits in seconds before booting the default entry
# Use `0' if you're sure that the default entry is correct, and you
# don't want to enter GRUB's user interface.
timeout 4 

# Tell which entry to boot by default.  Note that this is origin zero
# from the beginning of the file.
default 0

# Note that to GRUB, all hard disks are `hd' and all floppy disks are `fd'.
# To Mach, SCSI disks are `sd' and IDE type disks are `hd'.  Use
# GRUB names in the `root' command and prefixing filenames.  Use a
# Mach name as the `root' arg for the kernel, and whenever running the Hurd.

# color white/blue blue/green
# password xxx

# Entry 0: Windoze 2000
title Legacy OS: Win2000
unhide (hd0,1)
hide (hd0,2)
rootnoverify (hd0,1)
chainloader +1
makeactive

# Entry 1: Windoze 95
title Legacy OS: Win95
hide (hd0,1)
unhide (hd0,2)
rootnoverify (hd0,2)
chainloader +1
makeactive

# Entry 2: RedHat 7.1
title RedHat 7.1
root (hd0,8)
kernel /boot/vmlinuz-2.4.2-2 root=/dev/hda9

***

duncan wrote:
> 
> Hello all-
> 
> I have a box that uses grub as the bootloader (ive always used lilo
> untill now).
> 
> I had a dual boot, win2k, rh7.2 box.  I recently re-did the rh install,
> and in a rush, i think i installed the boot stuff on the mbr instead of
> the first sector.  So, now when i boot, my grub only has linux as the
> boot.  Im guessing that its an easy fix to the grub.conf file, but i
> havent clue what I am doing with it.
> 
> Anyone have anything to offer?
> 
> Thanks