Master Boot Record (MBR) belongs to boot record, along with Boot Configuration Data (BCD). MBR will be created when the first partition on the hard drive is created and it is a very important data structure on the first sector of disk, which contains the partition table for the drive as well as a small amount of executable code for the boot start.
Once the MBR file is damaged or inaccessible, you may not be able to boot your system at all, and error information as "Operating System not found", "Error loading operating system", "Missing operating system" or "Invalid partition table" will show up. If you receive any of these errors, you need to fix MBR in Windows 11/10/8/7 to get rid of the boot issues. Usually, the MBR problem might be caused by malware infection, or improper shutdown.
To repair damaged MBR in Windows 11/10/8/7, you can try the following two methods. If you can access Command Prompt in Windows RE mode (with using Windows installation media), choose the first one to repair MBR via Command Prompt. If you don’t have Windows CD, you can turn to the second method.
To access Command Prompt in Windows RE mode, you can try the below 2 ways:
After getting into the "Advanced options" screen, click on "Command Prompt" to launch it. Then type the command bootrec.exe and "Enter" to see the options that are available for this tool. (There are four parameter available : /FixMbr, /FixBoot, /ScanOs and /RebuildBcd. Each of them can help you solve different boot problems.)
Execute /FixMbr in Windows 10 with Command Prompt. (/FixMbr allows the repair of a corrupted or damaged Master Boot Record. And you should use it when you meet one of these error messages: "Operating System not found", "Error loading operating system", "Missing operating system" or "Invalid partition table".)
If you want to repair boot sector in Windows 10/11 without using Windows installation media or force restarting and shutting down the computer several times, you can use the free partition software: Qiling Disk Master Standard. That allows you to create a bootable USB drive on a working computer, then boot the PC with damaged MBR from it, and finally rebuild MBR within 3 steps. Now free download it on a working computer and follow the steps given below:
Step 1. Install and launch Qiling Disk Master Standard on a working PC. In the main interface, click Tools > Make Bootable Media and follow the wizard to create a Windows 10/11 bootable USB drive.
Step 2. Connect the bootable media created via Qiling Disk Master Standard to the computer with a boot issue and enter BIOS to boot computer from the USB drive.
Step 3. Once logged in, the Qiling Disk Master Standard will run automatically. In the Tools and utilities page, and choose Fix Boot.
Step 4. Click the system disk that contains corrupted MBR for Windows 10 in the pop-up window. (Choose a proper MBR type according to your operating system.)
Step 5. Click Proceed on the toolbar to commit Rebuild MBR operation.
With 2 methods shared, you can easily fix MBR in Windows 10 now. The second method can also be applied to repair MBR in Windows 7/8/8.1/11. If you want to experience more advanced functions, such as migrating Windows 10 to GPT disk, allocating free space from D drive to C drive, clone MBR disk to GPT, you can upgrade to Professional version.