How to Fix the MBR (Master Boot Record) in Windows 10

The MBR (Master Boot Record) is a set of information in the first sector of the system’s boot disk. It tells the computer where to find the operating system (or systems) and load it into memory. If something goes wrong with the MBR, it may not be able to boot normally. If you have a broken MBR, these are the most effective ways to repair the MBR.

How Does the MBT Become Damaged or Corrupted?

Although the MBR is a special area of the hard drive, it is not fundamentally different from any other data on the hard drive. This means that it is also vulnerable to the same threats. A sudden power outage can damage any area of a drive, especially if you are writing in that area. Viruses like malware can also deliberately alter your MBR to achieve their individual malicious goals.

Whatever the reason your MBR failed, there are several ways to repair it.

Use Automatic Repair

Windows 10 is a smart operating system and it can fix your problems much better than previous versions. Assuming your MBR is not completely destroyed, Windows will recognize that something is wrong at startup.

The message “Your PC did not start correctly” will appear and you will see options to restart the computer or select “Advanced options”.

How to Fix the MBR (Master Boot Record) in Windows 10

Under Advanced options, you’ll find Troubleshoot > Startup Repair.

Follow all the instructions and wait for the process to complete. This can take a long time because Windows creates the MBR by scanning the entire hard drive. However, at the end of the process, things should return to normal.

Use the Command Prompt to Fix the MBR

You can use the command prompt in Windows to manually start an MBR repair. If you see the Automatic Repair screen when Windows starts and you prefer to use the command prompt, choose Advanced Options> Troubleshooting> Command Prompt.

Once you’re at the Command Prompt, you can use a tool called Bootrec (Boot Recovery) to fix the MBR.

First, type BOOTREC /FIXMBR and press Enter. After a little while, you should see the message “The operation completed successfully.”

Congratulations, you’ve fixed the MBR, but your computer may still refuse to boot properly if you restart your system now.

So, just to be safe, type BOOTREC /FIXBOOT and press Enter.

After receiving the same confirmation message above, you can restart your computer to see if things are back to the way they should.

Use a Bootable Windows Disk to Fix the MBR

What if your MBR is so broken that you can’t even get Windows 10 to show you the automatic repair option at startup? In this case, only a few options remain open.

If all you want to do is reboot and you don’t have any critical information to back up, the quickest solution is to clean your boot drive and reinstall Windows. We especially recommend this if a corrupted MBR is only part of your general problems. When you are facing multiple errors and issues in Windows that resulted in MBR corruption, it is highly recommended that you consider replacing everything and solving multiple issues in one go.

If the only problem as far as you know is a corrupted MBR, you can also use a Windows 10 bootable installation media to access the repair function. Just boot from the Windows 10 installation media and instead of choosing Install, repair your computer.

After choosing the repair, you will have the same troubleshooting option as described above. You can also choose Command Prompt under Troubleshooting> Advanced Options and then use the same guide to repair MBR from the command prompt mentioned above.

If the MBR Is Corrupted Repeatedly

If you have repeatedly faced corruption issues with your MBR, you need to find someone to blame. If you are using a mechanical drive, MBR corruption may be the result of improper startup and shutdown. If your computer shuts down every time you visit again, consider purchasing an uninterruptible power supply (UPS) to counter poor power services.

Repeated MBR corruption can also be the result of a faulty hard drive. This applies in particular to mechanical hard drives, which are more prone to failure than modern solid-state drives (SSDs). If you suspect that your hard drive is corrupted, see How to Check Your Hard Drive for Errors. If your hard drive fails, back up your most important data and maybe use this as an opportunity to upgrade to an SSD.

If the hard drive or power supplier is not at fault, there could also be a faulty power supply unit (PSU) behind the computer suddenly shutting down. An overheated CPU that activates Failure Protection immediately cuts power and occurs when your cooling solution stops working properly.

Preventing MBR Corruption

Apart from physical drive failure, it can largely prevent the other causes of MBR from occurring. Make sure you have virus protection, practice basic safety precautions when running software from unknown sources, and shut down your computer properly instead of turning off the power.

As mentioned above, you can also make sure your computer doesn’t fail by using a UPS to give it time to shut down properly if the power goes out.