2x Windows XP on same HD
Have you ever tried to install 2 instances of windows xp on a single hard drive and wanted it so that each of those installations doesn’t see each other. I found out its not really a trivial task, actually it took me a while to get it working, but after some serious googling around I came up with solution to this problem.
I had very special case, I had ghost image of windows installation which I needed to have twice on same drive because of the 2 different software installations conflicting each other, changing software wasnt possible so I had to come up with something. Software only worked when installed to C: drive.
So first I deployed ghost image of the windows to the drive, activated it and did all necessary modifications for it. Then I booted computer with TRK and used ntfsresize tool to shrink windows installation to fit into first half of the drive. Then I started cfdisk tool and deleted partitions and created new partition table with 3 partitions, 2xwindows and 1 small linux partition.
Next I copied first partition to second using dd command, (dd if=/dev/hda1 of=/dev/hda2 bs=4096). Then I created ext2 filesystem on 3rd partition using mkfs.ext2 command.
So, in this point I had, 2xwindows and a linux partition on the hd. Next I installed grub (consult grub manual for this) on the drive and set linux partition as bootable. On grub’s menu.lst I made 2 entries for starting windows and used grub HIDE and UNHIDE commands
for the first windows first:
UNHIDE (hd0,0)
HIDE (hd0,1)
and for the second windows:
UNHIDE (hd0,1)
HIDE (hd0,0)
Now I had 2 x windows xp installations on the same drive as C: without any other visible partitions and everything worked fine 
This document is quite round in the corners but if you need help with the details dont hesitate to contact me