I use dd command to write a iso to a unformatted partiton
see if it can boot or not

I use windows and partitionmanager(from unetbootin)
I modified it a bit

so it will look like
c:\partitionmanagerrev120\ubninit
c:\partitionmanagerrev120\ubnkern
c:\grldr
c:\menu.lst

##menu.lst
title UNetbootin-partitionmanagerrev120
find --set-root /unetbtin/ubnkern
kernel /unetbtin/ubnkern root=/dev/ram0 init=/linuxrc ramdisk_size=100000 skip
initrd /unetbtin/ubninit
boot

I resize the partition of my windows
so
/sda
/sda1 , ntfs , windows , boot
/sda2 , new , 1G , unformatted

then I use the dd command in console
dd if=/path/winxp.iso of=/dev/sda2
sda2 now becomes a iso9600 partition
I can even use
mount -t iso9660 /dev/sda2 /mnt/winxp
to mount it

use grldr to boot see if it will work
##menu.lst
title boot iso9660
root (hd0,1)
savedefault
chainloader +1

...................of course, it wont work
googled a lot of pages, some crazy people think of it before, hundreds of pages, still no help
still thinking how to make it work