grub rescue> during windows 10 update [duplicate]

Question

I had ubuntu and Windows 8.1 simultaneously installed on 1 hdd and I Upgraded windows to windows 10, but during the installation, my laptop rebooted and now im stuck

error: no such partition. Entering rescue mode... grub rescue>

I treid the ls command to find the grub files, but it says "unknown filesystem" on all tge partitions

Answer 1

Take a look at this answer: windows 10 and ubuntu dual boot

Try to set prefix and root to every of the partitions. One of them should work and the system should boot.

You can also try boot-repair http://sourceforge.net/p/boot-repair-cd/home/Home/

Answer 2

First, boot from a Ubuntu Live CD or USB

Mount the partition your Ubuntu Installation is on. If you are not sure which it is, launch GParted (included in the Live CD) and find out. It is usually a EXT4 Partition. Replace the XY with the drive letter, and partition number, for example: sudo mount /dev/sda1 /mnt.

sudo mount /dev/sdXY /mnt

Now that you've done that, you need to bind the directories that grub needs access to detect other operating systems using the following commands.

sudo mount --bind /dev /mnt/dev &&
sudo mount --bind /dev/pts /mnt/dev/pts &&
sudo mount --bind /proc /mnt/proc &&
sudo mount --bind /sys /mnt/sys

Now you need to jump into it using chroot

sudo chroot /mnt

Now install, check, and update grub.

This time you only need to add the drive letter (usually a) to replace X, for example: grub-install /dev/sda, grub-install –recheck /dev/sda.

grub-install /dev/sdX
grub-install --recheck /dev/sdX
update-grub

Now that grub is 'back home' on your computer, you need to exit the chrooted system and unmount the drives

exit &&
sudo umount /mnt/sys &&
sudo umount /mnt/proc &&
sudo umount /mnt/dev/pts &&
sudo umount /mnt/dev &&
sudo umount /mnt

Just restart your computer and you'll be greeted with the default GRUB selection screen. Select Ubuntu and you're done!

Answer 3

Hey I just had the very same issue so I am posting my solution in case someone face it again.

I had a dual boot Windows 7 / Ubuntu 12.04. While trying to upgrade to Windows 10 I faced the grub rescue console and the same situation as this guy here.

First I tried to use it to solve my problem, but I couldn't find any partition containing my grub boot. Then I used Grub Boot Repair to repair my Grub boot which allowed me to complete my upgrade to Windows 10 as it was on the only bootable partition. You can use Rufus for example with a 2GB USB Drive to make your device bootable and change your boot priority in your BIOS.

In the mean time, I used GParted which happen to be on the Grub Boot Repair linux distribution and noticed that in fact my partition of Ubuntu was unallocated. So once I finished the upgrade, I used Free Minitool Partition Wizard as suggested by this guy to recover my partition directly from Windows 10.

After that, I used Grub Boot Repair once again to re-enable my original Grub Boot and bingo.