How to Restore Windows Boot Manager and Fix “BOOTMGR Is Missing” Errors

Encountering issues with your Windows Boot Manager can be a frustrating experience, preventing you from booting into your operating system. Whether you’re facing a “BOOTMGR is missing” error or your Boot Manager has disappeared from the UEFI BIOS, there are several troubleshooting steps you can take to restore it and get your system back up and running.

Restarting and Checking Boot Devices

The first step in resolving Boot Manager issues is to restart your computer and check your boot devices. Make sure there are no optical discs, USB drives, or floppy disks inserted, as these can sometimes interfere with the normal boot process. Additionally, check the boot sequence in your BIOS or UEFI settings and ensure that the correct hard drive or other bootable device is listed as the primary boot option.

Using the Startup Repair Tool

If restarting your computer and checking the boot devices doesn’t resolve the issue, you can try using the Startup Repair tool. This built-in Windows utility can diagnose and automatically fix many common startup problems, including issues with the Boot Manager. To access the Startup Repair tool:

1. Start your computer with the Windows installation media (USB or DVD).
2. On the “Install Windows” screen, select “Repair your computer”.
3. Choose “Troubleshoot” and then select “Startup Repair”.
4. Follow the on-screen instructions to let the Startup Repair tool analyze and attempt to fix the problem.

Repairing Boot Codes and BCD Errors

If the Startup Repair tool doesn’t resolve the issue, you can try manually repairing the boot codes and Boot Configuration Data (BCD) errors. To do this:

1. Start your computer with the Windows installation media.
2. Press Shift F10 to open a command prompt.
3. Run the following commands:
   • bootrec /fixmbr (to repair the Master Boot Record)
   • bootrec /fixboot (to repair the boot sector)
   • bootrec /rebuildbcd (to rebuild the Boot Configuration Data)
4. Restart your computer and see if the issue has been resolved.

Restoring Windows Boot Manager in UEFI BIOS

If the previous steps haven’t worked, you may need to restore the Windows Boot Manager directly in your UEFI BIOS settings. Here’s how to do it:

1. Enter your computer’s UEFI BIOS settings (usually by pressing a specific key during boot, such as F2, F12, or Del).
2. Navigate to the “Boot” or “Boot Options” tab using the arrow keys.
3. Look for an option to select the Windows Boot Manager as the primary boot device.
4. Save the changes and exit the BIOS, then try booting your computer again.

If the Windows Boot Manager is still not visible in the UEFI BIOS, you may need to use a third-party tool like AOMEI Partition Assistant Professional to back up and restore the Boot Manager settings.