How to Fix and Repair MBR on Windows 10

Theo Lucia

Apr 10, 2023 • Filed to: Windows Computer Solutions • Proven solutions

Fixing a Master Boot Record (MBR) may seem like a complicated process without the technical know-how but it is very easy if you have a perfect guide. In this tutorial, we aim to show you how to fix and repair MBR in Windows 10.

Overview of the MBR

MBR is a boot sector located in a region of a computer hard disk. This sector is responsible for storing information regarding all partitions in the hard drive. Master Boot Record also serves as a loading unit of the operating system in use. An MBR is created the moment you install Windows on an initial partition. If you look through your hard disk, you will notice a file with a size of about 512 bytes. That file is your MBR. A damaged MBR makes it impossible to boot Windows and there are so many issues that can lead to MBR damage. Some of them include

• Loading operating system errors
• Missing operating system error
• Invalid partition table error
• Bootable medium is not found an error
• Reboot and select proper boot device error
• Other types of errors determined by current factors

How to Fix and Repair MBR

To fix and repair MBR, here is a list of quick fixes. Each method has a detailed explanation for easy understanding. Use any of them to fix and repair MBR.

1. Startup Repair via Windows Automatic Repair

When you boot your Windows, it detects issues if there is any and once it does, it enters into what is called an automatic repair mode. You will see this message

"Your PC did not start correctly"

Select the Advanced Options – Troubleshoot and Startup repair to correct issues.  The Startup tool will work on the issues automatically after which your Windows will restart again.

2. Use Command Prompt Via Windows for Automatic Repair

If Startup does not fix the problem or you want a fast process, you can apply a direct approach by using command prompt through Auto repair. If an issue has been detected by Windows 10, the Repair screen will pop up.

Click Options – Troubleshoot– Command Prompt

To complete the repair procedure, use bootrec.exe to repair MBR. Bootrec.exe is highly recommended because it has a wide range of system commands meant for recovering boot processes. This tool also serves as an installation base for Windows.

• Type "bootrec.exe /fixmbr" then tap enter
• Type "bootrwc.exe/fix boot" then tap enter

Under each Command system will notify you if it is successful. If you see an error instead, type "bootrec.exe /rebuild cd" then tap Enter. This command will rebuild Boot Control Data.

• If the command does not work, explore BCD store and attempt a total rebuild with the following command

bcdedit /export c:\bcdbackup

C:

Cd boot

Attrib bcd -s -h -r

Ren c:\boot\bcd.old

Bootrec.exe /rebuildbcd

This process will repair all MBR problems

3. Fix MBR Issues using Gparted Live

Gparted live is a Linux enabled software for partition management. This software is very effective in fixing MBR related issues. To use Gparted, here are the steps

• Download Gparted  (32-bit or 64-bit)

  Both versions work for 32/64-bit. If your system is 32&64 bit, go for an i686.iso but for a 64-bit, choose an am64.iso.

• Write Gparted to Boot Media

  Download UNetbootin to write disc to the media type you are using. Click Diskimage and click the 3 dots icon for navigation to Gparted  ISO

• Choose ISO then click open. From there, choose USB drive then click OK. When the procedure is complete, disconnect bootable media then shut the system down
• Boot into Gparted

For corrupt MBR, insert the Gparted media into the device. Switch it on the open boot selection menu. When the menu comes on, look for Gparted Live as a bootable source. Click on it and leave it to load. Change the default language to your preferred language.

• After Gparted finishes loading, open Terminal Window and type in sudo fDisk -l then tap Enter. This command will show you a list of all partitions and drives. Choose No Log
• - The system will enquire about the disk in need of fixing. Select the drive
• Select the partition table. In our example our Partition table is Intel. Tap Enter button

• Click Analyze and then click the Quick search icon

Testdisk will perform a quick scan on your drive to identify primary Partition. The Partition to look out for is one with "*".  This primary partition contains the corrupted MBR. If you can't find it, conduct a Deep search for it. Live Gparted will also provide you with a list of errors found.

• If all the partitions found are in order, write the partition table but if they are incorrect use arrow keys to toggle them. (Use the example in the diagram below. Scroll over partition reveals the files it contains)
• The first duplicated partition is invalid which is why there is an error message in the diagram below

• The second duplicated partition contains folders in the correct partition

• The first one is ripe for delete with the D (Delete) indicator but the second one is set as L (Logical)

After you are through, close Terminal, log out Gparted and shut the system down before you remove Bootable media. Only after doing this should you reboot  PC

4. Fix MBR Issues Using Boot Repair Disk

Download a 33-bit or 64-bit  of Boot Repair Disk. Tick the Gparted Icon. Now, write a disk image to bootable media. Download UNetbootin too

• Open the UNetbootin section and select Diskimage. Hit the 3 dot icon to open Boot-Repair ISO
• Choose ISO and tap Open. Select the USB drive and tap OK.

Remove bootable media once you are done and shut down the system.

When boot repair loads, choose Terminal from Taskbar, type in fDisk -l then tap Enter to view partitions in the drive

• Select the B logo and navigate to System Tools section– Boot Repair. This program will do a system scan after which you may choose Automatic Repair to see Advanced options. Here you can try the first Automatic option to fix issues immediately

• If that fails, open the Advanced section and proceed to MBR options. Locate Windows partitions. Once you locate it, click Apply and restart your computer

We understand that many of our readers find it difficult to fix a faulty Master Boot Record hence our decision to address the issue using some of these technical solutions that have proven to work every time they have been used. If a particular solution does not work, try the next one until you find one that fixes the problem.