so you want to dual boot using the windows bootloader.
After booting with the rescue disk make sure you use chroot /mt/sysimage to get back into the system and not stay on the rescue-cd. Then make sure on which partition /boot is and use this partition name in the command (Where it says if=)
Also, BEFORE doing any of this, you need to install grub to the /boot partition. Otherwise it will not work!
You can find out what book a person needs by asking the question, "Do you want to be a Muggle or a Wizard?"
(1) If they answer "Wizard", then you give them RUTE.
(2) If they answer "Muggle", then you give them "Linux for Dummies."
(3) If they answer "What's a Muggle?", then you give them "Harry Potter".