If you need to DualBoot any system with GRUB, Use the following template to help you out......
Code:
 Originally posted here by ac1dsp3ctrum 
When you need to configure GRUB, open a window and type in /boot/grub/grub.conf
When you need to add an Operating System to GRUB do it like so (This is for Windows):

title OS Title
        rootnoverify (hdX,Z)
        chainloader +1

Where X is the hard drive number and Z is the partition number....
So if I had a Windows 2000 installation on Hard Drive 0 Partition 0 (Master Hard Drive on IDE1, 1st partition) I would type in this:

title Windows 2000
        rootnoverify (hd0,0)
        chainloader +1

This should make an option to boot Windows 2000 or whatever OS in GRUB... Hope this helps :D
Dont forget the indents