[bob]

And, that's the beauty of the instructions. You always have the option to switch in the BIOS to boot either OS, since each drive has it's own mbr. You can certainly add the Windows info to the Fedora grub boot and keep tweaking until Fedora boots both, but you won't risk losing anything or overwriting anything in the process.

As to the instructions, it's pretty simple really. Windows stays Windows - end of story on that drive. Fedora happily installs itself on the other drive, once Windows is pulled, and thinks it's the only OS in the computer. Even when the Windows drive is plugged back in, it doesn't concern itself with it. That's when you teach it by the 'mapping' instructions. You're essentially telling grub: "Hey, there's another drive and another OS that you should consider booting...look over HERE!"