By Emily / Last Updated October 30, 2019

MBR has corrupted in Windows 7, what will happen next?

The MBR (abbreviation for "Master Boot Record") is a boot sector (a region of your hard disk) that stores important information about the partitions of your hard drive. If the MBR on the secondary hard drive gets damaged, you will be unable to access this drive as usual. If the MBR on your primary hard drive is corrupted, you won't be able to boot your OS successfully and receive various error messages including:

  • Operating System not found

  • Error loading operating system

  • No bootable medium found

  • Reboot and select proper boot device

  • Invalid partition table

In such cases, you will have to fix MBR Windows 7/8/10 to make your external hard drive accessible again and OS boot back to normal.

How to fix and repair MBR in Windows 7/8/10?

So, how to repair MBR Windows 7/8/10? In this guide, you'll get a full guide to repair the Master Boot Record. Moreover, we will even introduce how to fix MBR without installation CD or DVD. Now, let's get started...

Part 1. Fix MBR in Windows 7 without CD/DVD

Sometimes, you might have found a great way to fix the boot record, but that required an installation DVD. What to do if you don't have one? Under this situation, you can turn to the free AOMEI Partition Assistant Standard, which allows you to create a bootable USB drive in Windows 10/8/7/XP/Vista and rebuild MBR in WinPE environment. Below is how to do it step by step.

Step 1. Connect an empty USB (it's better to be over 8GB) to a working Windows-based computer (since your Windows 7 cannot boot). Then free download the MBR repair tool.

Step 2. Install and run AOMEI Partition Assistant on that PC. Click on the "Make Bootable Media" in the left pane. Follow the wizard to create a WinPE bootable USB disk. Disconnect the USB drive after it is done.

Make Bootable Media

Note: AOMEI Partition Assistant Standard is pre-installed on the bootable drive.

Step 3. Plug the USB to your computer with a corrupted MBR, power up it and enter BIOS by constantly pressing Del (F2 or another specific key).

Step 4. Change boot priority to the bootable USB drive in BIOS. Press F10 to save the changes and restart computer to Windows PE mode.

Step 5. Once logged in, the AOMEI Partition Assistant Standard will load and start. In the main interface, right click the system disk you need to rebuild MBR and click "Rebuild MBR".

Rebuild Data Disk MBR

Step 6. A mini window will pop out, choose the proper MBR type for Windows 7 and click "OK".

Choose MBR Type

Step 7. Click "Apply" > "Proceed" in the main interface to commit the change.

Apply

Finally, remove the bootable drive and restart your Windows 7. If it is the secondary disk's MBR is damaged and cannot be accessed then, you can skip the steps of creating bootable USB drive, and directly run the software to rebuild MBR on the disk.

Part 2. Repair MBR in Windows 7 with installation media DVD

If you have kept your installation disc, you can try the following guide to fix MBR in Windows 7 with DVD.

First please put your original Windows 7 installation DVD into the computer's DVD or CD drive. Then do as the guide below.

Step 1. Boot your computer from the Windows 7 installation DVD.

Step 2. When the message "Press any key to boot from CD or DVD… "shows up, press any key to boot from the DVD.

Step 3. Select a "language", "keyboard layout" and click "Next".

Step 4. Select the operating system and click "Next". In the "System Recovery Options" window, click on "Command Prompt".

CMD Windows7

Step 5. When Command Prompt successfully launched, type the following commands and press enter each time:

  • bootrec /rebuildbcd

  • bootrec /fixmbr

  • bootrec /fixboot

Remove the installation DVD from the disk tray and restart your computer to check if it can boot up successfully.

If the above bootrec /rebuildbcd command fails to work, you can run the following command to export and erase the BCD store and use the Rebuildbcd command again to fix MBR Windows 7.

  • bcdedit /export C:\bcdbackup

  • c:

  • cd boot

  • attrib bcd -s -h -r

  • ren c:\boot\bcd bcd.backup

  • bootrec /rebuildbcd

Bonus guide: how to fix MBR in Windows 8/8.1/10 with CD?

Since different Windows 7 is different from Windows 8 and Windows 10, here we will also provide a detailed guide on how to repair MBR in Windows 8 and Windows 10 just in case.

Similar to the windows 7 MBR repair, you should first put the original Windows 8/8.1/10 installation DVD into the disk tray and boot your computer from it.

Step 1. At the Windows Welcome screen, click "Repair your computer".

Repair Computer

Step 2. Choose "Troubleshoot" > "Command Prompt".

Step 3. When the Command Prompt loads, type the following commands:

  • bootrec /FixMbr

  • bootrec /FixBoot

  • bootrec /ScanOs

  • bootrec /RebuildBcd

Fix MBR

Press Enter after each command and wait for each operation to finish.

Remove the DVD from the disk tray. Restart your computer and check if Windows can now boot.

Summary

Hope you all can fix MBR in Windows 7/8/10 by using the methods introduced in this article. Apparently, AOMEI Partition Assistant is a better choice. With it, you can effortlessly and easily fix MBR in Windows 7/8/10 32 bit or 64 bit instead of inputting the complex commands.

Besides, this versatile software could also empower you to check disk errors after the MBR repair in Windows 7, which will ensure there is no bad sectors on the system disk. If you want to fix or rebuild MBR in Servers, please try AOMEI Partition Assistant Server.