1] Check this thread about boot-132 loaders.

FRESH INSTALL

2] Download the image of my USB-Boot-132 Loader here. (Or better yet, follow this guide by stickpin.)

3] If you've followed the guide by stickpin, proceed to step 5. If not, borrow a computer with OSx86 or a real Apple one to modify the INITRD.IMG according to the needs of your motherboard & other devices. Just drag/drop any necessary kext(s).

4] Now open Disk Utility and restore the "BOOT132USB" to your USB-Flash Drive (at least 256MB capacity). Make sure you check the "Erase destination" option.

5] Follow this guide by llauqsd to prepare a self-booting (Retail) Leopard DVD Installer (boot-132 + retail leopard dvd installer into 1). But more importantly, the guide provides for installation in MBR partitions. Don't worry, the installer is still vanilla coz you're just "telling" it to recognize MBR partitions.

6] Now that you have your USB-Boot-132 Loader & a (Retail) Leopard DVD Installer for MBR partitions, let's get the installation started.

7] Boot your (target) computer with your (Retail) Leopard DVD (MBR) Installer.

8] After the "Choose Installation Language", open Disk Utility. Make three (3) partitions. 1st partition for your WinXP, 2nd partition for your Boot-132 (size should be a little bigger than the capacity of your USB-Boot-132 Loader), then 3rd partition for your Leopard. Make sure they're MBR partitions. 1st & 2nd partitions should be MS-DOS (FAT) and 3rd partition Mac OS Extended (Journaled).

9] Reboot and replace Leopard installer with Win XP installer. We'll have to install WinXP first. When you're happy with your Win XP, let's install Leopard.

10] Now let's boot with your (Retail) Leopard DVD (MBR) Installer again. Then open Disk Utility again.

11] Plug-in your USB-Boot-132 Loader and restore it to the 2nd partition. Make sure you check the "Erase destination" option. When done, exit Disk Utility.

12] Proceed with the Leopard installation.

13] After successful installation, open Terminal application before your computer automatically restarts.

14] We now have to make the 2nd partition (your Boot-132 Loader) active. Enter the following in Terminal:

diskutil list (lists your computers Hard Disk(s) and corresponding partition(s): take note of the Hard Disk where you have the partitions for the Boot-132 and your newly installed Leopard)

fdisk -e /dev/rdisk0 (where 0 is the appropriate disk identifier)

f 2 (where 2 is the correct partition number for your Boot-132)

write

y

exit

15] Quit Terminal and reboot.

16] At reboot, make sure you remove the Leopard installer from the optical drive and if everything goes well, you'd be presented with the options of either booting Win XP or Leopard.

17] Good luck and please post constructive feedbacks.