Creating Windows 7 and Centos 6 Dual boot from two different drives

Question

Windows 7 and Centos 6 are installed in different hard drives I would like to create a dual boot but I am not sure how to create a dual boot from windows 7.

Answer 1

The boot loader in Windows is unable to boot anything other than Windows, so you cannot do this from Windows 7.

Centos comes with grub, and grub can boot both Windows and Linux. The PC itself can only boot from one disk at a time, so choose one of the disks to be your boot disk, and install grub into the boot sector of that disk.

A basic grub 1 configuration (menu.lst) might look like this:

title=Linux
root (hd0,0)
kernel /vmlinuz root=/dev/sdb2 quiet

title=Windows
rootnoverify (hd1,0)
chainloader +1

So the first entry is saying to boot linux from the first partition of the first disk, and the second entry is saying to boot Windows from the first partition of the second disk.

Answer 2

The best way I found is while installing centos ask if you have any other os installed. I was selecting wrong hard drive. I selected sdb2 (sdb1 was for windows boot partition) and it worked fine.

Answer 3

You can change the OS boot configuration in the boo tloader with bcdedit, in a command prompt.

You only need to do it in Windows. Just set the BIOS to boot from that drive. I can't help with Centos but, if you have overwritten the windows bootloader with the one from CentOs, repair it from the Windows CD.