Repair grub2 from windows

It will have a label of EFI. Mount this partition, replacing sdXY with the actual partition number for your system:.

If you get errors or if going up to step 7 didn't fix your problem, go to step 8. Otherwise, it is optional. Compare it:. If you cannot boot normally, and didn't do step 8 because there were no error messages, try again with step 8.

The Windows installer doesn't care about other OS in the system. So it writes own code over the master boot record. Fortunately the solution is easy too. Then follow the following screenshots:. Documentation :. Then you can choose Ubuntu on the Windows 7 bootloader to go to Grub2 previous bootloader.

On EFI-based systems such as most systems that shipped with Windows 8 or later , Windows will sometimes update its boot loader or reset it to be the default boot loader. This is particularly common when re-installing the OS or performing a major system update upgrading to the latest Windows release, for instance. Everything needed to boot Ubuntu is still in place; it's just being bypassed.

In these cases, a complete re-installation of GRUB is overkill, and in fact that carries a small chance that it will create new problems. There are several ways to do this, including:.

Sometimes Windows insists on making itself the default every time it starts up, though, and reports indicate that bcdedit may do a better job of dealing with that problem. Boot-Repair worked for me. It's very very easy to use graphical application, you do not need to use the command line, you only have to click a button :. All the available repair options are described in the Ubuntu documentation and there is a separate page explaining how to start Boot-Repair by creating a bootable disk or installing it in an existing Ubuntu live disk and how to use it.

All of this has been made easy in a little graphical tool: Boot-Repair. It shall be integrated in Ubuntu Answers given by Scott and Web-E are good enough and have helped a lot many times. But many a times, the boot-repair tool is not able to repair grub due to problems related to i and amd64 platform or one where grub can't find efi directory. What has solved my problem like more than 10 times is to manually purge the old grub installations and install a new one.

So first perform the first 6 steps from Scott's answer where you can skip the 5th step if it gives an error:. If the problem still persists, you can read Arch's wiki to actually understand about grub to tackle many other varieties of problems. Yes, also helps for Ubuntu! Scott Severance's answer is valid and detailed but there is a resolution that requires no external boot device and so no need to identify and manually mount all of your Ubuntu partitions leading up to the chroot.

In Windows 10, you can use Advanced Recovery to select a device partition? Then choose Use a Device and all the boot options should be presented to you. Choose the 'ubuntu' partition and your PC should then boot from that partition. Once booted into my usual Ubuntu environment, I have tried just running grub-update but that made no change.

This has restored my master boot record multiple times now as there seems to be a new Windows 10 policy of overwriting boot info on minor updates. It turns out grub can be fixed from Windows too.

Running the following as administrator from CMD brought the grub menu back for me. Windows does not see Linux formatted partitions. Some have had issues if the new primary partition is after the extended partition as Windows does not always reset partition table correctly.

Best to have good backups and a separate backup of partition table. This is only for MBR msdos systems. Ubuntu Community Ask! Sign up to join this community. The best answers are voted up and rise to the top. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Learn more. How can I repair grub? How to get Ubuntu back after installing Windows? Ask Question. Asked 10 years, 1 month ago.

Active 1 year, 3 months ago. Viewed k times. How can I get Ubuntu back? Improve this question. Mattlinux1 2 2 gold badges 7 7 silver badges 23 23 bronze badges. Salahuddin Salahuddin 4, 7 7 gold badges 19 19 silver badges 19 19 bronze badges.

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Dual boot with win After an upgrade of win10, I booted into Mint and the system ater 10min gave a popup with only squares instead of fonts. Exit and reboot and from that time the system hangs either at the mint logo or on a black screen, no matter which kernel version I choose. A failsafe start drops me at the intrm loading and waits there. I tried booting with Rescatux and BootRepairDisk.

Both live distros , though, cannot reinstall grub2 claiming that the partition is readonly. Tried also to chroot into the system and reinstall grub from there, but still no success. Any ideas? Last edited by zagor. Re: Can't boot or reinstall grub2 after windows 10 upgrade Post by zagor.

But once the linux mint entry is chosen, the system hangs: vmlinuz is loaded, but intirmd is not and the system hangs showing "loading intial ramdisk I cannot edit and save the grub. Step 4: Restart the affected device and connect the USB to it. If none of the methods work to fix the grub rescue error, the only way left is to replace the hard drive, because in this case, the hard drive is damaged that is causing the grub startup issues.

Replacing the drive is the only good option. In case you want to rehabilitate your device and want to avoid grub startup errors, then follow the steps:. Here selects the file browser del boot option and click enter to continue. In the list of partitions, select the Linux partition you want to delete and click enter.

Save the changes by pressing F Restart your device. If you are dealing with the no such partition grub rescue error, for sure it is because of the issues related to the operating system. Using the dual operating systems, change made to any one of them can cause the grub startup error. Mostly it is because of changes linked to Ubuntu OS.

Deleting, resizing, merging, reinstalling, and shifting to an older version of the operating system can cause the grub rescue error. This article explained the reasons behind the error as well as the appropriate solutions to fix the error.

Some of the suggestions are also listed on the bottom to avoid any future consequences that could lead to grub error. Generally rated 4. Or trying to boot your device in grub rescue mode? This article will answer all your queries related to grub rescue and discuss relevant solution to fix grub rescue error. Download Win Download Mac. David Darlington. I had both Linux and Windows installed on my computer; I recently downloaded the upgrade to the 10 version before the free download expired.

The download did not completely go thru, I was prompted that there was a problem with the download. I continued to use my PC afterward and the next day I was unable to access the computer, as I am getting a "grub rescue" prompt. Looking on the Internet for ways to fix this, but am not that tech-savvy, and unsure if I can try to fix this issue. I understand some of what I am finding to solve the issue but am putting this post to see what feedback I may receive from the MS community.

I am not sure what version of Windows I had before the 10, I think it was 7, but not sure, and I do use Linux and want to get that back also. Thank you. You Might Also Like.

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