BOOTMGR is missing

What is BOOTMGR-MISSING?

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.

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

Commands & Diagnostics