Restore GRUB bootloader after a new Windows installation

GRUB is widely used bootloader for booting linux systems. It lets you choose the OS you want to boot from the list of all OSs loaded on your system.

If you install any Windows OS on your PC after installing Linux then you will not see the GRUB bootloader any more. Instead of that you will see only windows OSs will be listed now in the list. As Windows bootloader does not support Linux systems. So to get back your original GRUB bootloader you will have to do some changes in your Master Boot Record.

To do so you will require a live cd to boot linux. After booting from the live cd go to terminal and execute following commands.

sudo grub

find /boot/grub/stage1

Now it will show you the location of the drive on the hard disk where the GRUB loader is stored.

root (hd *, *)

setup (hd0)

quit

In place of * type the output you got with the previous command. Now restart your system and you can see your GRUB loader again.