i think just installing windows (98, XP or both) before installing linux will do the right job. Just follow the order: win98, winXP, linux. 98 will first write the MBR, then XP will modify it to accomodate both 98 and itself.
Finally, when u install linux, select grub as the boot loader (default in RH 8, 9) and install it on the MBR itself - works perfectly for me (i'v installed it many times using this approach on my pc as well as on several of my friends - and never find any probs). I tried not installing grub on the MBR once, and it gave some errors (don't even remember them now).
grub gives u two options at boot time - to load linux or the win boot loader. it 's a breeze then to boot into whatever OS.
hope that helps