General :: Chainloading Grub2 For A Multiboot Setup?

Don't know if I should have posted in Ubuntu specific section but since it involves grub2 and a quirk in my bios, I have attempted to multiboot 3 Windows versions and the problem I had was intalling a second Ubuntu. (Don't ask!) I had success multibooting with grub legacy on an older computer but this computer has a tricky mb which won't let me install grub to the second drive on an IDE port. What I mean by this is that since I already had boot files to the older drive in mbr- it won't allow me to install to mbr of the other drive in IDE port even if set first in bios boot order, my old computer allowed me to do so, exept perhaps its because 2 HDD were SCSI... (I have other HDD installed in RAID 0 on the other sata ports supported by mb (fakeraid) but I will use these for video editing as scratch disks later. One other HDD used for data is on the Raid port but not in an array).

I succeeded in installing Ubuntu desktop only after realising that I had to first switch my disk order in bios- otherwise the system would just hang. U. Desktop grub had sucessfully found Win bootloader links to both XP and Vista. I then installed Win 7 and used easy BCD and grub2 boot entry to link back to my Ubuntu Desktop grub 2 menu.

The problem occured when installing Ubuntu Studio ( for which I created a separate /boot partition) and I decided to install grub2 to mbr since it had correctly detected all my OSes! But then it seems it never installed correctly to the mbr. I still had Win 7 BCD bootloader in MBR! I tried to link easy BCD boot entry to the /boot drive but that didn't work and I ended up having to reinstall Win7 because I had overrid the BCD with faulty neogrub mapping entries- which I then removed and kept the orginal neogrub that still points to Ubuntu Desktop grub menu.

I also now realise that because I installed Ubuntu Desktop before I switched the HDD boot order in bios- U. Desktop's grub.cfg sees root of Desktop grub differently than neogrub BCD does root=(hd4,7) vs multiboot kludge (hd3,6) and at first I tried to install grub in the wrong hdds and partitions- I based mapping on neogrub's to find /Boot (hd3,2) and (hd3, 1) which is wrong!

What I am attempting to do now is to chainload grub2 from my Ubuntu studio located in /Boot with what I thought was the right mapping but still no success:

menuentry 'Chainloader' {
insmod chain
set root=(hd4,2)
chainloader +1
}

yielded error: hd 4,2 cannot get C/H/S values press any key to continue, also when in terminal in Ubuntu Desktop in
grub> find /grub/core.img
Error 15: File not found

I will attach Boot_info_script; at this point I am too tired and afraid that I will keep on installing grub to the wrong drive!

Note: I somehow got a problem loading into XP after all these failed attempts and a system 32 file seems to have gotten lost-haven"t attempted to fix yet. Just wondering in passing what happens if I chainloaded into Windows by error- if that could have corrupted it? Right now 3 out of 5 OS are bootable. I hope I can repair it without messing up my mbr again. Another issue is that some devices are on busy IRQs and then suddenly its resolved and my onboard LAN suddenly stops working at times so I don't know if any of this could cause XP to get stuck at loading screen.