$ sudo grub-install --root-directory=/media/ubuntu /dev/sda
From live CD mount(open) the Ubuntu installed drive.
Copy the location (press Ctrl+l, Ctrl+c ) eg: /media/ubuntuuuu
Open terminal (Apllication->accessories->terminal)
Type this:
sudo grub-install --root-directory=/media/ubuntuuuu /dev/sda
(replace /media/ubuntuuuu with what u got (ie paste))
Will show success message. Now reboot
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