As per the 2nd option (2. How to dual boot linux from windows xp with Wingrub?) mentioned in http://shamsweb.50webs.com/page3.html, you download WINGRB0206.EXE from http://prdownloads.sourceforge.net/grub4dos/WINGRB0206.EXE?download this place. After you install the program in C:\Program Files\WinGrub drive, doubleclick the program WinGrub GUI, Choose your drive (say C: ) and select the copy stage files checkbox from the window and then click ok.
Assuming,
* Your Kernel Version is 2.6.11-1.1369_FC4 (If not change the file names accordingly).
* Your hd1 is the external HDD and 0 is the partition mapped to /boot of your linux.
* /dev/sda2 is mapped to / (root) of linux
* You already created a new initrd with USB driver entering the shell prompt using "linux rescue" by booting from FC4 CD1 after mounting sda1 (mount /dev/sda1 /mnt/source/boot) and sda2 (mount /dev/sda2 /mnt/source) then (chroot /mnt/source) and finally by typing the command
mkinitrd --with-usb --preload=ehci-hcd --preload=usb-storage --preload=scsi_mod --preload=sd_mod ./usbinitrd-`uname -r` `uname -r`
Now open C:\Grub\MENU.LST file in your windows XP in Wordpad or Notepad and replace the existing text with the following and save that file. Do not include the comments #---
#---------MENU.LST Starts here ------------
timeout=20
root (hd1,0)
title Fedora Core USB
kernel (hd1,0)/vmlinuz-2.6.11-1.1369_FC4 ro root=/dev/sda2 rhgb quiet
initrd (hd1,0)/usbinitrd-2.6.11-1.1369_FC4.img
#---------MENU.LST Ends here --------------
If you might have installed your linux using LVM then replace the 4th line of the MENU.LST with the following
kernel (hd1,0)/vmlinuz-2.6.11-1.1369_FC4 ro root=/dev/VolGroup00/LogVol00 rhgb quiet
Open the Install Grub from the Wingrub tool menu, Select the System Drive i.e is the location of
BOOT.INI file,it's normaly C, in the Boot From list options, select the BOOT.INI , for
the title write Fedora Core and for timeout 20, now click on Install, this will
add the Fedora Core to the XP NTLDR, reboot and start the Fedora Core.