17 hours ago
So I have been trying to solve this problem from several hours for now:
I bought a new computer (HP OMEN 15) with Windows 11 already installed. I did a dual boot with ubuntu, which perfectly worked... until I booted again on Windows (from GRUB).
Then, GRUB disappears and only windows boot manager remains.
So I reinstalled GRUB according to these instructions: https://doc.ubuntu-fr.org/tutoriel/comment_restaurer_grub . And this worked, but the problem remained: upon launch, windows 11 erases GRUB again.
So then I inactivated windows boot manager following these instructions https://unix.stackexchange.com/questions/241809/grub2-gone-every-time-i-boot-windows-10 and I could clearly observe Windows boot manager was set inactive. So after that I reinstalled grub and ran agan efibootmgr but then windows boo manager was not in the list anymore. Ubuntu was standing where it was. So I thought "ok this time the problem is solved".
I double checked in my computer's BIOS: Windows boot manager had also disappeared and only "OS Boot Manager" was to be seen.
Upon boot, my computer properly open GRUB and I had the possibility to boot on ubuntu (which worked), or on Windows (even if there was no "Windows boot manager" either in the output of efibootmgr or in the Boot options list of my BIOS).
But still, when I chose to boot on Windows, the same problem happened again: GRUB disappeared.
What I think (with my low knowledge) it is related to:
What I need
I am in dire need of help. I would like to solve this disappearing GRUB problem and have a better understanding of what is going on here.
I am aware I may not have been clear enough, but I hope there is enough info for someone to help me !
Thank you for your reading time !