How to install grub for windows

Plenty of users have dual boot in their PCs. Most Ubuntu users have a Grub bootloader for booting. However, many users have recently reported that a Windows update overrides their Windows Boot Manager. This prevent users from booting in Ubuntu after updating Windows.

In this article, I have discussed how to install Grub bootloader in Windows 10 after a Windows update overrides it. By following the steps in this article, you will be able to fix Grub after Windows 10 upgrade.

Also learn how to convert MBR to GPT using MBR2GPT Windows 10 tool from here.

It is nuisance that a Windows update overrides the Windows Boot Manager to default boot using NT bootloader. After the Windows Boot Manager is overridden, it cannot recognize Ubuntu and thus cannot boot into it. Not only Windows update, but installing Windows after Ubuntu also does the same thing.

There is another case why your PC won’t boot into Ubuntu and that’s due to a faulty Grub file. In this case, you will have to repair Grub in order to fix this problem. I have given steps for both the cases below. Follow them carefully and you should be able to fix Grub after Windows 10 upgrade, fresh install, or a faulty Grub file.

1) Faulty Windows Boot Manager

The first case is the faulty Windows Boot Manager that occurs due to a Windows update or fresh Windows installation. To fix this issue, you will have to repair Grub from Windows. To do that, follow the steps given below:

1. Boot into Windows 10.
2. Press the Windows + R keys to open the Run utility.
3. Type cmd and press Ctrl + Shift + Enter to open an elevated Command Prompt.
4. Now, type the following command and press Enter:
   bcdedit /set {bootmgr} path \EFI\ubuntu\grubx64.efi

1. After you run the above command, it will change the bootloader back to Grub.
2. Restart your PC and you should be greeted with the Grub Menu.

However, there is a chance that after following the above steps you get the “System Bootloader not found” error. To fix this, you will have to disable the secure boot through UEFI firmware. To do it, follow the steps given below:

1. Reboot the PC.
2. Press the F2 or F10 key to open the Firmware settings during the boot screen.
3. Disable the secure boot. This option will differ for each system as the firmware settings will be different.

After you have disabled the secure boot, you should now boot into the Grub menu. From there you can boot into Ubuntu.

2) Repair Faulty Grub File

Sometimes a faulty Windows Boot Manager is not responsible for the Grub bootloader not working. It can also be due to a faulty Grub file. If the above step doesn’t allow you to use the Grub boot loader, it is likely for this reason. Now to fix it, you will have to use the Boot Repair. To use it, you will have to boot into Ubuntu, which you cannot do currently.

So, you will need a bootable USB or Ubuntu live CD. Download the Ubuntu ISO image from here and use any Bootable USB software to flash the image on your USB. Now, plug in the bootable USB or enter the Ubuntu live CD and restart your computer. After the computer restarts, follow the steps given below:

1. After you restart, select the Try Ubuntu without installing option in the booting screen to boot into Ubuntu.
2. Once, you boot into Ubuntu, open the Command line.
3. Type the following command and press Enter after finishing it:
   sudo apt-add-repository ppa:yannubuntu/boot-repair && sudo apt-get update
   This command will add all the Boot Repair tool’s repositories and also update them.
4. Now, type the following command and press Enter to download the Repair tool:
   sudo apt-get install -y boot-repair
5. Once the boot-repair file is downloaded, type the following command and press Enter to run it:
   boot-repair

The above steps will run the Boot Repair tool and it will automatically scan the disks in your system. After the scan is finished, the Boot Repair dialog will provide you with two options. Click on the Recommended repair option. Follow the on-screen information to complete the process. Once the repair tool is finished running, restart your PC.

Wrapping Up

That’s it. Now you know how to install Grub bootloader in Windows 10 after a Windows update. The above steps should do the job. If you have any questions related to this article, ask them in the comment section below.

The three interfaces of Grub functions at various levels. The menu interface consists of the list of kernels or the operating systems.

You have the option to select a particular operating system with the help of the arrow keys and you can boot it with the Enter key.

All the Commands in Grub are displayed in the menu entry editor interface. You can change the commands before you load the Operating System.

The Command-Line interface is the basic interface that provides the user with the utmost control. You can execute any command with the help of it.

You may sometimes encounter how to install a grub bootloader in windows 10 issues raised by the corrupted boot directory or the partition.

Restore Grub After Windows Install

The Grub Bootloader is particularly important as you cannot start the Operating System without it.

While you switch on the program, this is the first program that gets started. Then the Bootloader transfers the control it has to the Operating System Kernel.

When you are stuck with how to install a grub bootloader in Windows 10, you can go for a clean installation of Windows 10 or reset your BIOS settings. These may help you to resolve the problem.

You also have other options to fix it like rebuilding the BCD or simply replacing your damaged hard drive.

Through this article let us address the possibilities to fix the Grub related problem effectively.

Solution 1: Setting The Correct Partition 

If the correct partition gets deactivated somehow, you face this grub related problem and need to go for restoring grub after windows install.

This happens as the boot loader gets initiated by the BIOS from the active partition.

We suggest you verify whether the active partition is incorrect. Then you will have to get the proper partition activated.

This process works wonder to fix the grub related issues swiftly. Follow the steps mentioned below to execute the process:

Step 1: First of all you need to connect a DVD or USB Flash Player bootable media to your PC.

Step 2: Then give your system a fresh restart to execute the Automatic Repairing Process.

Step 3: Select to Troubleshoot and go to the Advanced options. Now, launch Command Prompt and enter diskpart and hit the Enter button.

Step 4: Input the commands mentioned below one after another:

• list disk: This will give you the list of all your hard drives
• select disk n: n denotes the disk where you have installed the operating system.
• list volume: All the Volumes on Disk 0 will be enlisted here.
• select volume n: he will give you the number of system partitions
• active: this will show you the active system partition. Identify the specific partition from the displayed list that ought to be active.

Step 5: Now, enter the commands given below and after inputting each one, press the Enter Key.

• select partition d
• active
• quit

Step 6: After you have finished the above step give your Computer a fresh restart.

Check whether your Grub related problem is solved this way.

Solution 2: Resetting the BIOS Settings

Resetting BIOS is another effective way to fix grub after windows 10 upgrade.

Here I am providing you a complete guideline to execute the task. Follow the steps:

Step 1: Turn off your computer and wait for a couple of minutes, then give it a fresh restart.

Step 2: Now, press F2 and repeat the process till you see the System Screen Window.

The function key may vary from system to system. Give it a check while you start your system.

Step 3: Now with the help of the Right Arrow Key go to the Exit menu bar.  Then move on to the Load Optimized Defaults.

Step 4: After you pressed the Load Optimized Device option, hit the Enter button.

After you accomplished the entire procedure check whether this has helped. You also have the option to flash the BIOS of your computer to fix the issue.

Solution 3: Using the Automatic Repair and restoring the Boot Sector Code

You may use your automatics repair system provided by Windows 10 and run are repairing process for restoring grub after windows install.

The boot sector code may be damaged and this may create the problem. So, you need to restore the boot sector code so that the grub rescue error is not prompted.

For this, I am describing the process that you are required to follow meticulously.

Step 1: Give your PC a fresh restart for repeated times and then select to Troubleshoot. From the displayed panel, choose Advanced and from there move on to Start-up Repair.

Step 2: Now, the repairing process will commence. Wait till the procedure gets completed.

We recommend you not to proceed for any operation in between. After that check, if that was good enough to address your problem.

Step 3: You have another option to use DVD or USB Flash Drive for resting the boot Sector Code.

For this, connect the bootable USB or DVD to your PC give your computer a fresh restart to go to the Automatic Repair Mode.

Step 4: Now proceed to Troubleshoot and then go to the Advanced Tab.

Step 5: Now Enter cmd to launch Command Prompt. Input the given commands in the Command Prompt. Do not forget to hit the Enter button after you type them.

diskpart

select disk 0

list volume

This way you will get all the volumes displayed. In the Type section, you will get to see DVD-ROM.

Make sure to remember the letter for the drive of the DVD or USB Flash Drive that you have connected to your Device. Like D or E.

Step 6: Now, enter the commands that I am providing below and click Enter.

Exit

D: or E:

CD Boot

Dir

Step 7: Scrutinize whether there is bootsect.exe file in the provided list. On finding it input the given command and then hit the enter button.

bootsect /nt60 SYS /mbr

Exit

Step 8: Now reboot your Computer and hope this will solve the problem you are muddling with.

Solution 4: Clean Installation Of Windows 10

To repair grub from windows, install Windows 10 afresh so that the installations done previously completely get removed.

For this, you will have to download the ISO file of Windows 10 on another device and get it burned on a DVD. You may also proceed with creating a USB drive that you can boot.

You may take the help of a third-party utility or you may also fix the boot related error if you create a bootable media.

That will automatically help you launching the program, selecting the proper partition, etc.

Solution 5: Rebuilding BCD With The Help Of Windows 10 Automatic Repair

If you cannot find bootsect.exe file, then you may need to rebuild BCD to combat your Grub issue.

Many users have reported that by using this rebuilding BCD technique they could easily fix the Grub related issue.

Follow the given process described below to rebuild the BCD:

Step 1: First of all you will have to connect bootable USB Flash Drive DVD to your system.

Step 2: Then reboot your PC and go to the Automatic Repair Mode.

Then from the advanced window choose Command Prompt for initiating BCD Files.

Step 3: Enter the below-given commands in the Command Prompt and when you have finished press Enter:

• Bootrec /Fixmbr
• Bootrec /Fixboot
• Bootrec /Rebuildbcd

Step 4: When you complete the process, exit from Command Prompt and then give your device a fresh restart.

Solution 6: Replace The Hard Drive

Sometimes you may face several issues with your hard drive. Your hard drive may get damaged somehow and this may lead to the Grub rescue issue along with other burning issues for your system.

In case you discover that your hard drive is damaged, we suggest you replace it immediately.

Hard Drives are available on your manufacturer’s website or from the retail sites then replace your drive and clean install Windows 10 to get rid of the Grub related problem.

Winding Up

Hope the resolutions provided could give you the answer to how to install grub bootloader in Windows 10.

If you still have queries or issues with the related files, feel free to intimate us in the comments section or may shoot us a mail.

We always look forward to hearing back from you.