We often come across a condition in which the boot loader gets corrupt. Here are a few steps that will help you recover your GRUB 2 boot loader.
Boot from a live CD or DVD, which supports GRUB 2 ([highlight1]Ubuntu 9.10 CD or above[/highlight1]. A DVD will take more time than a CD, so I suggest you boot from a CD).
Open the terminal and run fdisk -l to check the partition from which you want to recover GRUB 2.
Here I assume that you want to recover it from /dev/sda1.
Then run the following commands:
$sudo mkdir /media/sda1
$sudo mount /dev/sda1 /media/sda1
$sudo mount –bind /dev /media/sda1/dev
$sudo mount –bind /proc /media/sda1/proc
Now chroot into that partition by running the command given below:
$sudo chroot /media/sda1
Then re-install GRUB, as follows:
#grub-install /dev/sda
The output should be like what’s shown below:
Installation finished. No error reported.
If you get an error, then try the following command:
#grub-install –recheck /dev/sda
[highlight2]After a successful installation, exit from chroot and unmount the file systems that were mounted to recover GRUB. Now reboot.[/highlight2]
#exit
$sudo umount /media/sda1/proc
$sudo umount /media/sda1/dev
$sudo umount /media/sda1
$sudo reboot
You’ve successfully completed, recovering of GRUB boot loader.