Recovering the GRUP 2 Boot Loader
Boot by Ubuntu Linux Live CD

Easy to download and create from – http://www.pendrivelinux.com

Decide where you need to install GRUP 2
Step 1: List the linux partitions
# sudo fdisk -l
You can find the linux partitions from this list

Note:  GRUB 1 – starts from sda0 but GRUB 2 – starts from sda1

Mount the partition where you need to install GRUP 2

# sudo mount /dev/sda5 /mnt
# mount

Mount the partition to different location
# sudo mount /dev/sda5 /mnt/boot

Create an unbreakable link from the /dev folder on the live image you booted from to the /dev folder on the partition you monuted to /mnt
# sudo mount –bind /dev /mnt/dev

CHROOT from the live images’s root to the mounted partitions’s root
# sudo chroot /mnt
if you do ls now it will list all files & directories from the mounted parition

Reinstall the GRUP 2 boot loader to the drive on which exists the partition you mounted previously
# sudo grub-install /dev/sda
Installation finished. No error reported
no need to put sda5 – partition number

Exit your CHROOT level
# exit
now you are in the live CD image root path

Cleanly unmount all the partitions you previously mounted
# sudo umount /mnt/dev
# sudo umount /mnt/boot
# sudo umount /mnt

Now you can reboot and make sure to unplug the USB or remove the CD/DVD
# sudo reboot