Score:0

Windows replaced Ubuntu's GRUB

ye flag

I am using Ubuntu with windows 11 as dual boot but due to faulty update from Microsoft, I have to reinstall windows 11. Now, windows 11 replaced Ubuntu's GRUB.

How to recover grub?

I have an SSD with two partitions — one for windows and the other for Ubuntu.

sudodus avatar
jp flag
You can try with [Boot Repair](https://help.ubuntu.com/community/Boot-Repair)
ChanganAuto avatar
us flag
If UEFI (and it must be for Windows 11) then **no, it didn't**. It merely changed the boot order. Please open UEFI > Boot where you'll find "Windows bootloader manager". Simply change it back to "Ubuntu". Boot Ubuntu and run `sudo update-grub`.
Score:1
fi flag

First, check with your PC-Motherboard/Laptop Manufacturer to know about the hotkey to press on start up to enter into Boot options, before your Windows11 is booted. There you will see option to Boot from Operating Systems you installed in your storage drives, select Ubuntu from it.

After booting into your Ubuntu, open your Terminal application then run:

sudo update-grub

This will update your Grub and rewrite your EFI partition.

sudodus avatar
jp flag
Sorry, but this is not enough. `sudo update-grub` will not fix the problem with the EFI partition.
ChanganAuto avatar
us flag
@sudodus What makes you think there is a problem with the EFI partition? Reinstalling Windows 8/10/11 with a preexisting ESP simply adds its bootloader (or replaces a previous Windows bootloader), it doesn't create problems for other installed OSes.
sudodus avatar
jp flag
Maybe I have misunderstood the text in this answer. I'll reread it carefully. @ChanganAuto, When I converted Windows 10 to 11 some time ago, it high-jacked my dual boot via grub, and update-grub did not help. So obviously something is wrong in the EFI partition. I don't mean the partition structure itself, but the content. It is possible to fix it manually, maybe as simple as you suggest in your comment at the question, but update-grub is not enough. At least it is/was not enough in my case after Windows 10 --> 11, and I remember other instances too with major updates of Windows 10.
sudodus avatar
jp flag
I saw 'Boot menu', but now I see , SamGregory, that you mean changing the order for booting in a 'Boot options' submenu in the UEFI/BIOS menu system, and I am with you: +1 :-)
kumar pradeep avatar
ye flag
Sorry but update grub command doesn't fullfill my task.
Sam Gregory avatar
fi flag
Sorry didn't think too much about the EFI system @kumarpradeep, I am not adding this into my answer, as I am not sure if this is the right solution for your problem. try running `grub-install --target=x86_64-efi --bootloader-id=grub_uefi --recheck`
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