How to install grub for Ubuntu

LIVE BOOT with ubuntu 64 BIT only

lauch Gparted check ext4 parition of ubuntu note down (e.g. /dev/sda7 then let x=a and y=7)

First, open the Terminal and execute below commands




Mount partition

sudo mount /dev/sdXY /mnt
sudo mount --bind /dev /mnt/dev
sudo mount --bind /dev/pts /mnt/dev/pts
sudo mount --bind /proc /mnt/proc
sudo mount --bind /sys /mnt/sys

sudo chroot /mnt

Install Grub 

grub-install /dev/sdX

grub-install --recheck /dev/sdX

update-grub

Now unmount all

exit
sudo umount /mnt/dev
sudo umount /mnt/dev/pts
sudo umount /mnt/proc
sudo umount /mnt/sys
sudo umount /mnt

All done!! just reboot your system