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Fixing Missing GRUB After Dual-Booting Ubuntu and Windows 10

Ubuntu 8

In the world of operating systems, dual-booting is a common practice that allows users to run two different operating systems on the same machine. However, this setup can sometimes lead to a few issues, one of them being the disappearance of the GRUB (Grand Unified Bootloader) after installing Ubuntu alongside Windows 10. This article will guide you through the process of resolving this issue and restoring your GRUB.

Understanding the Issue

Before we dive into the solutions, it’s important to understand what GRUB is and why it might be missing. GRUB is a bootloader package developed to support multiple operating systems and allow the user to select among them during boot-up. If you’ve installed Ubuntu after Windows 10 and you don’t see the GRUB menu, it means that your system is directly booting into Windows 10, bypassing the GRUB.

Solution 1: Disable Fast Startup in Windows 10

Fast Startup is a feature in Windows 10 that allows your computer to start up faster after shutdown. However, it can cause issues with the GRUB when dual-booting.


  1. Boot into Windows 10.
  2. Navigate to Control Panel -> All Control Panel Items -> Power Options -> Choose what the power buttons do.
  3. Click on “Change settings that are currently unavailable”.
  4. Uncheck “Turn on fast startup”.
  5. Restart your computer and check if the GRUB screen appears.

If this doesn’t solve the issue, try the next solution.

Solution 2: Set Ubuntu as the First Boot Option

Your computer’s BIOS/UEFI settings manage the order in which the installed operating systems boot up. If Windows 10 is set as the first option, the system will boot directly into Windows, bypassing the GRUB.


  1. Restart your computer and enter the BIOS/UEFI settings. (The key to enter these settings varies depending on your system’s manufacturer. Common keys are F2, F10, F12, or DEL.)
  2. Navigate to the boot options list.
  3. Set Ubuntu or the option that mentions Ubuntu’s boot loader (GRUB) as the first boot option.
  4. Save the changes and exit.

If you don’t see the Ubuntu option in the boot options list or if the problem persists, proceed to the next solution.

Solution 3: Use the Command Prompt in Windows 10

You can use the Command Prompt in Windows 10 to set the path for the bootloader.


  1. Boot into Windows 10.
  2. Open the Command Prompt as an administrator. (Go to the Start menu, search for “Command Prompt”, right-click on it, and select “Run as administrator”.)
  3. In the Command Prompt, copy and paste the following command: bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi
  4. Restart your computer and check if the GRUB screen appears.

In the command above, bcdedit is a built-in command-line tool that controls the boot manager. The /set parameter sets a specified value in the Windows boot configuration data store (BCD). The {bootmgr} argument is an identifier for the object that represents the boot manager. The path parameter specifies the path to the file that should be loaded.

Solution 4: Use Ubuntu Live USB

If the above solutions don’t work, you can use an Ubuntu live USB to fix the GRUB.


  1. Boot into the Ubuntu live USB.
  2. Open a terminal and run the following commands:
    sudo mount /dev/sda4 /mnt
    sudo grub-install --root-directory=/mnt/ /dev/sda
    sudo update-grub
  3. Restart your computer and check if GRUB appears.

In the first command, sudo mount /dev/sda4 /mnt, mount is a command that attaches the filesystem found on a device to the directory tree. /dev/sda4 is the device, which in this case is the partition where Ubuntu is installed. /mnt is the directory where the filesystem will be attached.

The second command, sudo grub-install --root-directory=/mnt/ /dev/sda, installs the GRUB on the MBR of the first hard drive. --root-directory=/mnt/ specifies the directory where the GRUB files will be installed.

The third command, sudo update-grub, updates the GRUB.


If none of the above solutions work, it is possible that there may be an issue with the installation or configuration of GRUB. You may need to reinstall Ubuntu, ensuring that you follow the correct installation steps and properly configure the bootloader. Always remember to backup your data before attempting any changes to your system.

What is GRUB and why is it important?

GRUB (Grand Unified Bootloader) is a bootloader package that allows users to select among multiple operating systems during boot-up. It is important because it enables the dual-booting of different operating systems on the same machine.

How do I know if my GRUB is missing?

If you have installed Ubuntu alongside Windows 10 and you don’t see the GRUB menu during boot-up, it means that your system is directly booting into Windows 10, bypassing the GRUB.

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