Insert the Ubuntu LiveCD into the CD/DVD drive and reboot the computer. The machine boots from the LiveCD.
Click the “Try Ubuntu Without Installing” icon from the LiveCD “Start” menu. Ubuntu boots from the LiveCD.
Click “Applications” from the top taskbar in the Ubuntu desktop, and then click “Accessories.”
Click the “Terminal” option. The Ubuntu command-line terminal opens.
Type the following command at the prompt and press the “Enter” key. Replace “sdax” with the name of your “root” partition linux 8300.
sudo -i
fdisk -l
mount /dev/sdax /mnt
mount --bind /dev /mnt/dev
mount --bind /dev/pts /mnt/dev/pts
mount --bind /proc /mnt/proc
mount --bind /sys /mnt/sys
chroot /mnt
grub-mkconfig -o /boot/grub/grub.cfg
grub-install --root-directory=/mnt /dev/sda
grub-install --recheck /dev/sda
umount /mnt
reboot