SDB:Booting Windows from the Second HD
Version: 8.1
Situation
You want to boot a DOS/Windows operating system from the second hard disk with the boot manager Grub.
Procedure
A DOS/Windows OS can usually be booted from the first hard disk only. However, if you want to boot Windows from a hard disk other than the first, you can simply change the hard disk's BIOS number to make Windows "believe" it resides on the first hard disk. This can be achieved in the Grub configuration with the comand map.
To do this, open the file /boot/grub/menu.lst with an editor of your choice and edit or append the following section:
title windows root (hd1,0) makeactive chainloader +1 map (hd0) (hd1)
map (hd1) (hd0)
Save the file menu.lst. The changes will apply immediately.
If the boot process freezes with the message "grub", change the line
root (hd1,0)
to
rootnoverify (hd1,0)
The labels in the configuration file are explained in the article SDB:The Boot Manager Grub
SDB:Booting Multiple Windows Installations from One Hard Disk
<keyword>grub,boot,windows</keyword>