How to repair Grub Boot Loader on Ubuntu or restore or reinstall Grub on Ubuntu. Install Boot-Repair application than can be used to repair Grub on Ubuntu Linux. Boot-Repair is a simple tool to repair frequent boot issues you may encounter in Ubuntu like when GRUB is not displayed anymore, some upgrade breaks GRUB, etc.
Boot-Repair repair MBR-locked OEM computer boot if the original bootsector has been saved by Clean-Ubiquity. It can also repair the boot when you have the “GRUB Recovery” error message. Boot-Repair also has advanced options to back up table partitions, back up bootsectors, create a Boot-Info (to get help by email or forum), or change the default repair parameters: configure GRUB, add kernel options (acpi=off …), purge GRUB, change the default OS, restore a Windows-compatible MBR, repair a broken filesystem, specify the disk where GRUB should be installed, etc.
Install Boot Repair
RUn the following commands in terminal to install Boot Repair on Ubuntu 16.10, Ubuntu 16.04, Ubuntu 15.10, Ubuntu 15.04, Ubuntu 14.10, Ubuntu 14.04 and other Ubuntu Derivatives:
sudo add-apt-repository ppa:yannubuntu/boot-repair
sudo apt-get update
sudo apt-get install boot-repair
Using Boot Repair
Once installed open the Boot Repair from Ubuntu Dash.
When you start the Boot Repair for the first time, it will scan the system for any possible damage or error. This scanning process may take some time depending on the system. Once the scan is complete you will see the Boot Repair window.
There are two options.
- Recommended repair
- Create a BootInfo summary
The Recommended repair option is what you should select. It will repair all the most frequent problems.
To do so, click the “Recommended repair” button. When repair is finished, note the URL (paste.ubuntu.com/XXXXX) that appeared on a paper, then reboot and check if you recovered access to your OSs.
Boot-Repair lets you fix these issues with a simple click, which (generally reinstalls GRUB and) restores access to the operating systems you had installed before the issue.