How to Repair Windows 7 Boot Loader

What is Windows boot loader and what can it do on Windows PC?

The Windows boot loader, also known as Windows Boot Manager (or BOOTMGR), is a small piece of software that loads and transfers control to the operating system (OS) kernel when you start your computer. It is the first part of the Windows startup sequence and is responsible for presenting users with a menu if multiple operating systems are installed.

Here's how the boot process works:

1. BIOS/UEFI Initialization: When the computer is powered on, the BIOS (Basic Input/Output System) or UEFI (Unified Extensible Firmware Interface) performs a power-on self-test (POST) and then locates the bootable device (e.g., hard drive).

2. BOOTMGR Activation: The BIOS/UEFI loads the Windows Boot Manager (BOOTMGR) from the boot sector of the active partition. And Boot Manager will find the system partition (often the C: drive).

3. Boot Configuration Data (BCD): BOOTMGR reads the Boot Configuration Data (BCD) file, which contains a list of installed operating systems and their startup configurations.

4. OS Selection: If multiple operating systems are installed, the boot loader presents the user with a selection menu, allowing them to choose which OS to boot. If there's only one OS, the boot loader continues automatically.

5. Kernel Loading: BOOTMGR loads the necessary OS files, including the Windows kernel (ntoskrnl.exe), and then transfers control to the kernel to continue the boot process.

What will happen when Windows Boot Loader corrupted, damaged, or missing?

When the Windows Boot Loader is corrupted, damaged, or missing, the system will fail to boot into Windows properly. Instead of loading the operating system, you may encounter one of the following symptoms:

So, when Windows boot manager has problems, the worst thing is that you can't turn on Windows system. So many users may not know how to access Windows tools to fix the problem. What's more, many reasons might cause BOOTMGR damaged.

Corrupted Boot Configuration Data (BCD): If the BCD file is damaged, BOOTMGR cannot load the necessary OS files. Missing or Corrupted System Files: Malware could accidentally delete, corrupt, or modify critical boot files. Hard Drive Issues: Hard drive corruption or failure can prevent the system from finding BOOTMGR. File Compression or Disk Fragmentation: Compression of the system partition or BOOTMGR file can cause issues. Improper Shutdowns: Sudden power loss or improper shutdowns may lead to boot loader corruption.

How to repair Windows 7 boot loader/ BCD via Windows 7 Installation Media

In this part, we'll show you how to repair Windows 7 BCD and with Windows built-in tools and how to use handy tool to repair Windows BCD when your computer can't boot normally. But first, you may need to prepare a Windows 7 Installation Media, because you'll need to start your PC into the Windows Recovery Environment.

Tip: Since Windows 7 has also removed the Windows 7 ISO download page from its official website, you can only search for it on the website.

If you boot your computer from an installation disc, click through until you reach the initial Windows installation page, then click the "Repair your computer" link rather than starting the installation.

Select the Windows 7 operating system that requires repair, and then select "Next." Click Command Prompt in the System Recovery Options dialog window to carry out a boot repair in Windows 7.

Type Bootrec.exe, and then press Enter. Then input these commands and execute one by one:

▪ bootrec /FixMbr

▪ bootrec /FixBoot

▪ bootrec /ScanOs

▪ bootrec /RebuildBcd

A better alternative to repair Windows 7 boot loader easier

If you have Windows 7 Installation Meida to use CMD to fix BCD Windows 7, many users can find commands to be really difficult. Here we so provide a simpler fix for your Windows 7 boot loader damage. Comprising a complete disk and partition manager, AOMEI Partition Assistant Professional lets you handle your partitions in resizing, merging, disk copy, rebuild MBR, etc.

This Windows disk and partition manager's "Boot Repair" feature is intended to fix missing or corrupted BCD files. It provides customers with a simple and effective way to quickly bring back the normal boot capability of their computer.

Step 1. Install and launch AOMEI Partition Assistant on a working PC, click "Recovr"-"Boot Repair" and then click the "create a bootable disk" option to create a WinPE "Boot Repair" disk.

Step 2. Follow the instruction, you can enter the guide to create window for creating a Win PE bootable Media. Please download ISO file that fit your OS.

Step 3. After you create a boot repair disk for Windows, you can plug the bootable disk you created into the target computer you wish to repair the boot issue.

Step 3. Enter BIOS in your computer, choose the bootable disk as the boot drive to access AOMEI Partition Assistant.

Step 4. The PC that cannot boot into WinPE will automatically load the Boot Repair tool and start the boot entries scan process. After the process is completed, it will display the scan result: system paths, system versions, and boot status. And, all repairable boot entries will be available to select.

If you click "Advanced Options", you can customize the a location to store the repaired boot entry.

Step 5. Select one/multiple repairable boot entries you want to repair and click the "Repair" button to start the boot repair.

Step 6. Wait for the repair process to finish. Once it is finished, you can check the repair result. If it succeeds, you will get a "Repair Successfully" result.

Now you can remove the USB and boot your computer to check.

Conclusion

How to repair Windows 7 boot loader? Now you must know the answer. If you can prepare a Windows 7 Installation Media and you are familiar with the commands, you can use both tools to try to repair BOOTMGR and fix boot manager missing in Windows 7. But, if you want an easier way, AOMEI Partition Assistant can be a reliable method to quickly repair Windows 7 boot issues.