When your computer’s Grub bootloader stops working, you can use a live CD to fix it. A live CD is a CD that boots your computer into a Linux environment, which you can use to fix your computer.
To fix Grub from a live CD, you will need a live CD of Linux and a USB flash drive. The live CD should be a distribution that you are familiar with so that you can navigate its menus.
First, boot your computer from the live CD. Once you are in the Linux environment, open a terminal window.
Next, insert your USB …