Thanks for clarifying how the HD numbers are interpreted from the dd command's output, meierfra.
But here's another important thing I noticed:
On boot-up, if I enter the Grub CLI, if I do the "find /boot/grub/stage1" command, it finds (hd0,1) which I know is the partition that the MBR points to. BUT, if I enter the Grub CLI after I've booted into one of my linux distros (using "sudo grub"), the "find /boot/grub/stage1" command returns both (hd0,1) and (hd0.3). To clarify, I have 4 partitions like such:
Thus it seems like when I do the "find /boot/grub/stage1" command from the boot-up Grub CLI, I get the partition the MBR points to. But if I go to the Grub CLI from within one of my Linux distros and do the same command, Grub returns ALL my partitions that contain a Grub stage1 file, and not just the partition that the MBR points to.
(hd0,0) = Windows
(hd0,1) = Ubuntu (has Grub installed)
(hd0,2) = Swap space
(hd0,3) = Mandriva (also has Grub installed, but Grub was installed to the boot sector of its partition, not to the MBR)
Can someone please either confirm or clarify this?