How to Fix Grub Boot Loaderd in Ubuntu/Linux mint

Boot-Repair is a simple tool to fix Grub boot loader issues

 
    How to Install Boot-Repair

1. Either from an Ubuntu live-session or from your installed Ubuntu session (if you can access it) 
2. connect to the Internet open a new Terminal, then type the following commands (press Enter after each line)

                     sudo add-apt-repository ppa:yannubuntu/boot-repair
                     sudo apt-get update
                     sudo apt-get install -y boot-repair