How to Fix Missing GRUB Boot Menu after a Windows Update

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You’ve installed your favorite Linux distro alongside Windows and have been happily enjoying the best of both worlds, without having to override your Windows installation. This is possible thanks to the incredible bootloader: GRUB.

Until one day you notice that the GRUB boot menu no longer appears, causing your computer to automatically boot on Windows — locking you out of your Linux installation. If you have been plagued by this issue, cursing Linux or GRUB will be of no help. The real culprit here is Windows.

Here is what actually happened. Unlike GRUB which is intelligent by design to detect the presence of other operating systems, the Windows bootloader doesn’t take into account other operating systems that are installed on the computer. Whenever a major Windows update is available, the GRUB bootloader gets replaced by the Windows bootloader. Therefore, in order to bring back the GRUB boot menu, all we have to do is replace the Windows bootloader with GRUB.

The instructions below explain how to restore / reinstall GRUB on Ubuntu, Debian, Manjaro, Arch Linux and other derivatives.

Step 1: Boot from a Live USB

First, you need to boot from a live Linux USB. Then, open a Terminal window.

Step 2: Identify Root Partition and EFI Partition

Run the following command to determine the current root and EFI partitions:

lsblk -io KNAME,MOUNTPOINT | grep "/"

List / View root and EFI partitions on Linux

We’ll now create shell variables to denote the root and EFI partitions:

Caution

Make sure to set the variables $ROOT_PART and $EFI_PART with the proper partition names you obtained above! Also, don't forget to add /dev/ in front of the partition name as shown below:

export ROOT_PART="/dev/nvme0n1p5"
export EFI_PART="/dev/nvme0n1p1"

Step 3: Mount Root Partition and EFI Partition

Next, mount these partitions and set proper permissions:

sudo mount $ROOT_PART /mnt
sudo mount $EFI_PART /mnt/boot/efi

sudo mount -o bind /dev /mnt/dev
sudo mount -o bind /proc /mnt/proc
sudo mount -o bind /sys /mnt/sys
sudo mount -o bind /run /mnt/run
sudo chroot /mnt/

Step 4: Fix GRUB Installation

Once the proper partitions have been mounted, run the appropriate commands below depending on your Linux distro.

Ubuntu and Debian derivatives (For UEFI or Non-UEFI):

sudo apt-get install --reinstall grub-efi
sudo update-grub

Manjaro and Arch Linux derivatives (For UEFI):

sudo pacman -S grub efibootmgr os-prober
sudo grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=grub
sudo grub-mkconfig -o /boot/grub/grub.cfg

Manjaro and Arch Linux derivatives (For Non-UEFI):

sudo pacman -S grub
sudo grub-install --recheck --target=i386-pc $ROOT_PART
sudo grub-mkconfig -o /boot/grub/grub.cfg

Step 5: Reboot

Finally, restart your computer and you should be good to boot on Linux again :)

sudo reboot

Tip

If you still don’t see the GRUB boot menu, you’ll need to change the boot order in the BIOS. It is also possible to do this from Windows without entering the BIOS as explained below.

Changing GRUB Boot Order in Windows

The following steps will enable you to change the boot order priority to set GRUB as the preferred bootloader without entering the BIOS.

Step 1

In Windows, click on the Start Menu and search for “Command Prompt”.

Step 2

Right click on the Command Prompt menu option and click “Run as administrator”.

Note

It is important to open the Command Prompt with Administrator privileges, otherwise the step below will not work!

Open Windows Command Prompt as administrator

Step 3

Copy and paste the appropriate command below depending on your Linux distro in the Command Prompt window and press ENTER:

For Ubuntu:

bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

For Manjaro:

bcdedit /set {bootmgr} path \EFI\Manjaro\grubx64.efi

For Arch Linux:

bcdedit /set {bootmgr} path \EFI\Arch\grubx64.efi

Next, reboot your machine and you should see the GRUB boot menu again :)

# Footnotes

https://wiki.archlinux.org/title/GRUB

https://www.bleepingcomputer.com/forums/t/734220/lost-my-grub-menu-on-manjarowin-10-dual-boot/

https://askubuntu.com/questions/1001822/trouble-with-dual-boot-after-windows-10-update-used-bcdedit-now-cant-access-b

Comments

GUEST

Jan Wegner

Wednesday, Feb 8, 2023 at 07:17 UTC

What if I have an “extra” /boot-partition like

export BOOT_PART="/dev/nvme0n1p4"

and it is mounted on a previously mounted “/” export ROOT_PART="/dev/nvme0n1p5"

Will a $> mount $ROOT_PART "/mnt/root"; mount $BOOT_PART /mnt/root/boot"

do the trick?

advTHXance Jan

ADMIN

Ray Jan Wegner

Thursday, Feb 9, 2023 at 19:06 UTC

Unfortunately, I have not tried a setup having 2 boot partitions on the same disk. I reckon the second boot partition /dev/nvme0n1p4 is a non-EFI partition that lacks the ESP flag?

If yes, I’d probably do it like this on Ubuntu and Debian derivatives distros:

export BOOT_MNT="/mnt/root/boot"
export BOOT_PART="/dev/nvme0n1p4"

sudo mkdir -p $BOOT_MNT
sudo mount $BOOT_PART $BOOT_MNT

sudo apt install --reinstall grub-efi
sudo grub-install --recheck --target=i386-pc $BOOT_PART
sudo grub-mkconfig -o $BOOT_MNT/grub/grub.cfg

DISCLAIMER: This is just pure speculation. I have not tested this one and won’t be held liable for any data loss or corruption which might occur! At your own risk…

Wednesday, Feb 8, 2023 at 20:03 UTC

In step 4 above “Fix GRUB Installation”

in the section: “Ubuntu and Debian derivatives (For UEFI or Non-UEFI):”

sudo apt-get install --reinstall grub-efi # ok

the following line upgrade-grub

leads to a “upgrade-grub: command not found”

Do you mean sudo update-grub?

Sourcing file ‘/etc/default/grub’ …
…
Generating grub configuration file …
…
done

at least at my mint 21.1

Thursday, Feb 9, 2023 at 18:38 UTC

Hi Jan,

Thank you for pointing this out. There was indeed a typo in the command. I’ve updated the instructions to use update-grub instead of upgrade-grub.

DianaB.

Tuesday, Sep 5, 2023 at 10:55 UTC

Hi,

when I run “export $ROOT_PART="/dev/nvme0n1p7” I get the following response: “zsh: /dev/nvme0n1p7 not found.”

do you know why this is? And how can I fix it?

I’m using Manjaro.

Thanks a lot.

Ray DianaB.

Tuesday, Sep 5, 2023 at 18:47 UTC

Hi, thanks for bringing this up. There was a typo in the command. You should remove the dollar sign in front of the variable in the export command:

export ROOT_PART="/dev/nvme0n1p7"

Bernd Dreyer

Friday, Nov 24, 2023 at 10:30 UTC

What if Ubuntu menu entry disappeared after update Ubuntu update to Ubuntu 23.10.1 (Mantic Minotaur). The installation routine requests a decision of hold the old grub or not. I have voted for the old grub.

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How to Fix Missing GRUB Boot Menu after a Windows Update

Restore Missing GRUB Boot Menu

Step 1: Boot from a Live USB

Step 2: Identify Root Partition and EFI Partition

Step 3: Mount Root Partition and EFI Partition

Step 4: Fix GRUB Installation

Step 5: Reboot

Changing GRUB Boot Order in Windows

Step 1

Step 2

Step 3

# Footnotes

Comments

Leave a comment

How to Fix Missing GRUB Boot Menu after a Windows Update

Restore Missing GRUB Boot Menu

Step 1: Boot from a Live USB

Step 2: Identify Root Partition and EFI Partition

Step 3: Mount Root Partition and EFI Partition

Step 4: Fix GRUB Installation

Step 5: Reboot

Changing GRUB Boot Order in Windows

Step 1

Step 2

Step 3

# Footnotes

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