I have dual boot on my Lenovo Thinkpad T420s, Windows 10 and Ubuntu 22. Actually I had, because I tried to reinstall Ubuntu 22 and I’ve lost my dual boot and ability to boot at all. So I tried few things: reformat manually EFI and root partitions os-prober and update-grub setting root and prefix at grub rescue grub-install Windows installation troubleshooting Unfortunately it does not work. Something went terribly wrong. To bring back Windows first boot from installation media and go for command prompt: This way I was able to boot into Windows once again, but unable to do it