Fix bootmgr is corrupted the system cannot boot in Windows 10


We often get asked ‘How to fix bootmgr is corrupted the system cannot boot in Windows 10?’ Let’s start from the beginning.

What is BOOTMGR in Windows?

When a computer is switched on, the BIOS looks for the MBR code in the first hard drive it finds. This MBR code takes certain actions to load BOOTMGR.

The BCD (Boot Configuration Data) is a kind of an essential boot loader file that allows different operating systems to operate on the same computer. When these files become damaged, the process of booting will probably be affected. Because this error BOOTMGR image is corrupt is due to faulty BOOTMGR files. However, there are several options for resolving this problem on your own.

In this post, I’ll show you how to repair the system that can’t boot due to a corrupt BOOTMGR image in Windows.

Let’s begin:

1. Check the boot sequence of your computer

This problem occurs when the incorrect disk is listed first in the boot sequence. Optical drives that are not bootable include external hard drives, floppy disk drives, and USB flash drives. As a result, be sure to verify the BIOS’ boot sequence. If not, move the hard drive to the top of the list.

To verify that Windows is loading from your hard drive and not a recovery drive or external disk.

  • Go ahead and restart by clicking the “start” button on the bottom left corner of your screen where it says “shut down”.
  • After pressing shut down (not restart), a window will pop up asking you to choose an option.
  • On the far left side of this new window, select “Troubleshoot”.
  • Now click advanced options again.
  • Then on the window that pops up next, select “startup settings” and click restart.
  • After clicking restart, your computer will boot into a blue screen with some white text on it. This is called the BIOS menu.
  • From here press F5 (F2 or DEL on some computers). A different screen should pop up after pressing one of these buttons where you can change what items are listed in the boot order, which what item gets selected when your computer first turns on.
  • Be sure to put Windows Boot Manager as the first thing in the boot order, and the hard drive is installed on a second.
  • After making these changes, save them by pressing F10 or clicking “apply” and then close this window with “OK”.
  • Now select “reboot” from the bottom of the screen and your computer should reboot. When it does, you should be able to choose windows normally.

2. Fix the Bootmgr

  • Boot your computer using the installation iso or USB drive you created when you installed Windows 10 for the first time
  • When the setup starts press shift+f10 to get a command prompt window
  • Type disk part and press enter
  • Type list volume and press enter (note: this will show all of the drive letters that are connected to your computer, it will be easier if you write down which one is which)
  • Type select volume 1 and then type active and finally type exit (and yes you did need to replace “volume 1” with whatever letter yours was) (this makes it so that we can install windows where we want).
  • Now type cd boot and press enter (this makes it so that we can see what’s in the bootable files)
  • Type dir and press enter (and note all of the stuff in here because you will need this for later).
  • Type cd winre and press enter (this makes it so that we can make a backup of your old files to replace them with after we fix them).
  • Type rename c:\boot\bcd bcd.old and press enter.
  • Now type bootrec /FixMbr and press enter
  • Now type bootrec/fixboot and press enter. Then just restart your computer normally.
  • When you’re back at the setup page, just leave it alone for 5 minutes or so and come back to see if it works.

If you were successful, your system should boot up normally and give you the setup page again.

3. Rebuild your BCD

  • “Start your computer in safe mode with networking” – you may need to restart your PC 5 or more times before it boots into safe mode successfully
  • When you are booting up the first time, press F8 for advanced options
  • Once in safe mode click Start and type: cmd
  • Then right-click cmd and select run as administrator
  • If everything is working correctly a black screen will pop up and say:
  • C:\WINDOWS\system32>_ (maybe a slightly different version number)
  • Type: bootrec /rebuildbcd
  • When that finishes copying files type: exit
  • You should be back at the command prompt, now type shutdown -r -t 0
  • If everything is successful you will now be able to boot into windows!

4. Restore your computer

To do this, follow these steps below:

  • Click on the top left corner of your screen where you can see the time and date.  From here click on the Settings cog under “Accounts”.  This should bring up a pop-up menu like in the picture below.
  • Select “Power”
  • From here click on “Restart” at the bottom right-hand side of this new menu window.
  • Once the computer has restarted you will be presented with three options.
  • Click “Troubleshoot”
  • Click “Advanced Options”.
  • Click on “System restore”.
  • Once the system restore has opened select the date you would like to go back to.

If you get something like the below…proceed to Step 6.


5. Reinstall Windows 10

Download the Windows 10 iso from here:

  • Double click the Windows 10 iso.
  • Click through till you see the screen where it says – Install Windows 10 and Keep your files
  • Hit OK
  • Your computer should reinstall Windows and get you back on the fresh install in a couple of minutes or hours depending on the speed of your computer.

6. Replace the hard drive

If all of these techniques fail, there’s a chance that the hard drive is broken. The hard drive may be dead, preventing the computer from booting up. In this situation, you’ll have to replace the hard drive and set up a fresh copy of Windows on it. Melbourne based Computer Technicians are skilled at repairing computers and making sure all your files, settings, and applications are intact on your new hard drive.


I am a computer engineer holding a bachelor's degree in Computer Science, complemented by a Master's in Business Administration from University of Strathclyde, Scotland. I currently work as a Senior IT Consultant in Melbourne, Australia. With over 15 years of...