Fixing Linux Bootloader Issues - northern-bites/nbites GitHub Wiki

This problem has been encountered by many when trying to boot Linux in their computers. It is relatively easy to recover/re-install GRUB in Ubuntu from live CD/USB (if you cannot find one ask Kote to teach you how to make one). This tutorial will teach you how to use Boot-Repair, a simple graphical tool that can restore or reinstall the grub bootloader on Ubuntu.

###Symptoms

  • Ubuntu not booting
  • When presented with OS selection there is no countdown that automatically boots the selected OS
  • Instead of booting the selected OS, you get a blinking cursor on the black screen

###To Reinstall GRUB Boot Ubuntu from live CD/USB, while booting choose Try Ubuntu. Once booted open terminal and run the following commands one by one to repair GRUB.

  1. Add boot-repair to the repository
    sudo add-apt-repository ppa:yannubuntu/boot-repair
  2. Update your repository
    sudo apt-get update
  3. Install boot-repair
    sudo apt-get install -y boot-repair

Once the installation is done, run boot-repair in the terminal.
NOTE: Update boot-repair if there is a new version.

Let boot-loader scan the system and then click Recommended Repair to start repairing GRUB.
system scan
start repair

Once the repair is done, click OK and restart your system. Your GRUB should work now and you should be able to boot Linux. If for some reason your computer still does not want to boot run boot-repair (you will probably have to repeat all of the above steps) again from live CD/USB.

Select Advanced Options; in Main Options tab check if Reinstall GRUB and Unhide Boot Menu for 10 seconds are selected, if not select them.

Then check the GRUB location tab and make sure that OS to boot by default and Place GRUB to are selected and set to what you want them to be. Click apply.

This should repair your system. Click OK and restart your system.

If this does not work, talk to someone before going to IT.

source: HowOpenSource