Booting Troubles: Yet Again!!! ARRGGG

[SL6-A1000]

Hey,
Ok, with all the booting issues i have had, this is an issue i haven't ever run into before.

See i recently had to re-install Windows XP/7(upgrade disc), due to a major system stuff up, which in turn not only prevented me from booting Linux but managed to change my Extended logical partition into a primary partition, totally screwing that entire Linux partition's within (god how i hate windows bootloader).

Getting past my rant & how i got to this issue, i have re-installed all Linux OS's. My current issue is that whenever i have my Windows HDD in the system it will automatically override the Grub Bootloader installed on my Linux HDD.
Thus, i can boot linux through grub no problems, and i can boot windows no problems, but only when both hard drives are not present at the same time.

So for info:
The layout is:
Linux LVM+Boot: Hard Drive 1 & 2
Windows XP/7: Hard Drive 3

I have tried re-setting up Grub several times using the live-cd while all hdd's are installed, but this doesn't work.

My suspicion is that i have 2 MBRs and the windows MBR is overriding all others. But as i said when i reinstalled linux i made sure grub was installed on the MBR. So i do understand quite how this has happened.

Any help would great

[devils casper]

If you have more than one Hard disk, then best way of dual booting is, keep both OSes in separate disks and just add an entry of Windows OS in GRUB installed in other Hard disk.
First of all, check if Windows OS and Linux boot up fine independently. Unplug all Hard disks except disk having Windows OS. Does Windows OS boot up fine? Do the same with disk having Linux and check if Linux boot up fine.
If both OSes working fine, plug-in Hard disk having Linux as Primary and other disk having Windows OS as Secondary (Slave). You can do this through cable select or ( Jumper settings in IDEs).

If you using GRUB2 then run update-grub command as root user. It will detect Windows OS and setup dual boot. In case you are using GRUB, add chainloading code in grub.conf file.

[SL6-A1000]

Thanks, it wasn't exactly what i was after, but it prompted me to look into my BIOS settings, which i didn't think off earlier. The re-installation of Windows must have changed the boot order of the hard drives under my BIOS settings. So that hd3 was master and hd1 was the slave.
Which explains why my system was only booting into Windows when hd3 was plugged in.