BOOTMGR is missing

What is BOOTMGR-MISSING?

BOOTMGR is missing (BOOTMGR-MISSING) is a critical-severity fault affecting the Windows operating system. The 'BOOTMGR is missing' error appears at startup before Windows loads. The Windows Boot Manager (BOOTMGR) is the first program loaded by UEFI/BIOS to find and launch the Windows OS loader. If BOOTMGR is missing, corrupted, or on a partition that is not marked as active/bootable, Windows cannot start at all. The steps below are ordered to resolve this efficiently.

Common Causes

• Corrupt MBR or Boot Sector
• Bootable partition not marked active
• Drive disconnected during boot

Step-by-Step Fix Guide

• 1
  Boot from Windows installation USB and run Startup Repair

  The bootrec command suite is the standard Microsoft tool for repairing the BCD store and MBR without reinstalling Windows.

• 2
  Use bootrec /fixmbr and bootrec /fixboot

  If bootrec /fixboot fails with access denied, disable Secure Boot and Fast Boot in BIOS first.

• 3
  Verify boot drive is properly connected and detected in BIOS

  "Verify boot drive is properly connected and detected in BIOS" targets corrupt MBR or Boot Sector, one of the documented causes of BOOTMGR-MISSING.

Commands & Diagnostics

Frequently Asked Questions