How to recover grub after Windows installation

Question

Usually when we install Windows after installing GNU/Linux, we usually lose the Grub. Which is the best way to recover grub when we lost grub or what are the possible different ways.

Solution 1

You need to boot system using LiveCD of ubuntu and run below command to install grub :

sudo grub-install /dev/XXX

above command will install grub and it also Keep windows bootloader NTLDR into grub , then you can choose any one OS while boot.

/dev/XXX this is your HDD where ubuntu installed (eg: grub-install /dev/sdb).

Please refer below link for more information :

https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows

Solution 2

Late but the problem is as recent as it can be. I managed to avoid creating an up-to-date Live CD/USB stick to issue the recommended range of commands. From within Windows 10 Command Prompt (not PowerShell!) with admin rights, I used:

bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi

for EFI Secure Boot. You can normally use

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

More details and screenshots here and here.

Comments

[Gilles 'SO- stop being evil']

Related: How can I prevent Windows from overwriting GRUB when using a dual-boot machine

[David Magalhães]

At least for Windows 7 didn't work.

[Mario]

Hi, I see, W7 was the one back then, so which errors did you get if any? Unfortunately, the guides I used assume that W10 is installed. I added that detail.

[David Magalhães]

No errors. But on restart nothing changed.