Boot Repair : Installed Win after Linux

Ubuntu

When you install Linux after installing Windows i.e dual boot, everything works well but we need to reinstall GRUB bootloader if we installed Linux after Windows. 

The application named Boot-Repair lets you to reinstall GRUB- bootloader. It also allows to restore the original boot sector (MBR).

Get Live CD of Ubuntu and boot that live CD.

Now follow the below given commands.

sudo add-apt-repository ppa:yannubuntu/boot-repair

sudo apt-get update

sudo apt-get install boot-repair-ubuntu

After installing go to GNOME Desktop and find System > Administration > Boot Repair.

Now you can easily reinstall GRUB with a click.