The update finished, the PC restarted, and your Ubuntu option vanished. This frightens almost every dual boot user once — and it is almost never data loss. Windows updates rearrange the boot order; rarely, the Ubuntu entry itself is damaged. This page repairs both, from the two-minute fix to the deep one.
Start with the calm fact: a Windows update does not delete Ubuntu, its partitions or your files. What it regularly does is put Windows Boot Manager back on top of the firmware boot order — and occasionally, a bigger feature update rewrites the EFI boot entries themselves. Repair in this order: reach Ubuntu once, restore the order, and only if the ubuntu entry itself is gone, rebuild it. Nothing here requires reinstalling either system.
Restart and tap your PC's one-time boot menu key — commonly F12, F8 or Esc. If an ubuntu entry is listed, choose it. GRUB and Ubuntu will start normally, which tells you the update only changed the order.
Do this check before downloading any repair tool. In the large majority of post-update cases, the entry is sitting right there and step 2 is the whole job.
Inside Ubuntu, one command shows the firmware list and one command fixes it. This is the same repair as the missing menu guide, repeated here because after an update it is the one you will actually use.
sudo efibootmgrsudo efibootmgr -o 0001,0000 with your numbers, ubuntu firstHonest expectation: a future feature update may do this again. It is a two-minute repeat, not a recurring fault, and it is the known tax of dual booting on a Windows-first machine. Some users pin the order inside the BIOS setup instead, which survives a little better on some models.
If no ubuntu entry exists anywhere, the EFI entry itself was lost. The friendly route back is Boot Repair, a free tool that runs from a live Ubuntu USB and rebuilds the entry and GRUB in one pass.
sudo add-apt-repository ppa:yannubuntu/boot-repair, sudo apt update and sudo apt install boot-repairboot-repair and click Recommended repairRecommended repair rebuilds the GRUB installation and re-registers the ubuntu entry — exactly the two things an update can disturb — and leaves both systems' files untouched.
Recommended repair (repairs most frequent errors) — this option reinstalls GRUB and restores the boot entries. Your documents and both operating systems are kept.
The deep repair, for when Boot Repair cannot run or does not finish: reinstall GRUB by hand from the live USB. You mount the installed Ubuntu, mount its EFI partition inside it, step into it with chroot, and install the bootloader as if you were Ubuntu itself.
lsblk — say it is /dev/nvme0n1p5 and the EFI partition is /dev/nvme0n1p1sudo mount /dev/nvme0n1p5 /mnt and sudo mount /dev/nvme0n1p1 /mnt/boot/efifor i in /dev /dev/pts /proc /sys /run; do sudo mount -B $i /mnt$i; donesudo chroot /mnt, then run grub-install --target=x86_64-efi --efi-directory=/boot/efi --bootloader-id=ubuntuupdate-grub, then exit, unmount and restartPartition names here are examples — using the wrong one mounts the wrong system, so confirm yours with lsblk first. When the commands complete without errors, the ubuntu entry is registered again and GRUB is rebuilt.
You cannot stop Windows from preferring itself — it is designed to. You can make the recovery boring instead of scary.
With those three habits, a post-update missing menu is a two-minute detour, which is all it ever really was.
See the setup these repairs protect — the complete dual boot installation from the video, live and step by step.
▶️ Watch Full VideoNo. Windows updates do not touch Ubuntu partitions or files. What the update changed is the boot arrangement — it either put Windows Boot Manager first in the firmware order, which hides GRUB, or in rarer feature updates disturbed the ubuntu EFI entry. Both are repaired on this page without reinstalling anything.
If the ubuntu entry still exists, about two minutes: boot Ubuntu from the one time menu and reorder with efibootmgr. If the entry itself is gone, the Boot Repair route takes around fifteen minutes including booting the live USB. The manual chroot repair is the last resort and takes a little longer.
Small monthly updates rarely disturb the boot order; the big feature updates are the usual suspects, and even they usually only reorder it. Keep the live USB and the efibootmgr command handy and each occurrence is a two minute fix. A BIOS level boot order sometimes survives better on some laptop models.