How to fix the BOOTMGR is missing error in Windows

BOOTMGR (Windows Boot Manager) is the boot loader of Windows: a hidden, read-only file normally located on the System Reserved partition (the active partition, without a letter). From there loads the volume's boot code and starts Windows by executing winload.exe and the rest of the necessary components.

If Windows cannot read or locate that driver, you will see messages like:

• "BOOTMGR is missing. Press Ctrl+Alt+Del to reboot."
• "BOOTMGR is missing. Press any key to reboot."
• "The BOOTMGR image is corrupted. The system cannot boot."
• "BooTMGR could not be found"

These warnings appear after the POST and before Windows boots., and can be due to software, hardware or configuration.

Common causes of the "BOOTMGR is missing" error

The origin can be varied, but the most common causes are these:

• BCD/BOOTMGR damaged or misconfigured (corrupt boot configuration data).
• Boot sector or MBR defective or non-existent.
• Incorrect boot order in BIOS/UEFI, or the PC tries to boot from non-bootable media (USB, CD/DVD, floppy disk).
• Disk with bad sectors, file system errors, or corruption.
• Loose or damaged SATA/power cables and disk hardware problems.
• Problematic Windows Updates o human errors (deleting system files, partition changes).
• Outdated BIOS or misconfigured.
• Power outages or voltage spikes during boot that damage the boot sector.
• Malware which affects the MBR/boot sector.

Quick checks you should do first

Before we get started with advanced tools, try these basics. and check after each one if the equipment starts:

• Restart the computer with Ctrl+Alt+Del or by holding down the power button for a few seconds; sometimes the warning is just a one-off.
• Remove all external devices (USB, cards, disks, DVDs) to prevent it from trying to boot from non-bootable media.
• Reset and reconnect the SATA and power cables of the internal drives with the PC off; a loose connector can cause the error.
• Hear strange noises in mechanical records (clicks, buzzing sounds); if they appear, stop using them and consider data recovery services.

Adjust boot priority in BIOS/UEFI

An incorrectly set boot order causes the computer to "look" for the system in the wrong place.. Make sure the Windows disk is installed first:

1. Turn on your PC and enter BIOS/UEFI. by pressing the indicated key (usually Del, F2, F10, F12 or ESC).
2. Go to the Boot menu and locate Boot Order/Boot Sequence.
3. Place as first device the drive where Windows is installed.
4. Save and exit (usually F10) and try rebooting.

If the order was the problem, this should make the message go away.If it persists, continue.

Automatic Repair from Windows Recovery Environment (WinRE)

Startup Repair detects and fixes common startup errors. In Windows 8/10/11, the system itself often enters WinRE after several failed attempts; in Windows 7 You usually need an installation media or a repair disk/USB.

1. Boot into WinREIf the “Choose an option” screen doesn’t appear, boot from the Windows USB/DVD and click “Repair your computer” on the first screen.
2. Go to Troubleshoot > Advanced options > Startup Repair.
3. Select your Windows installation and let the tool do its work; it may restart automatically.

Nota: if automatic repair indicates that it cannot be repaired or if it does but the error returns upon restart, move on to the console methods.

Repair MBR, boot sector and BCD with Bootrec

Bootrec.exe is the Swiss Army knife for fixing MBR, boot sector and rebuilding BCD.. Run the commands in this order from WinRE:

1. Enter WinRE from the installation media if necessary and choose Troubleshoot > Advanced options > Symbol of the system.
2. Identify your system drive (often C:, but may vary in WinRE). Replace with C: and press Enter if appropriate.
3. Write and execute, one by one:
   • bootrec / fixmbr (writes a Windows-compatible MBR)
   • bootrec / fixboot (writes a new boot sector)
   • bootrec / RebuildBcd (scans systems and rebuilds the BCD store)
   • chkdsk / f (optional but recommended to fix file system errors)
4. Type exit and reboot to test the boot.

These commands fix most boot corruptionsIf it doesn't locate facilities or the BCD is empty, add the detected system when prompted.

Regenerate the boot environment with BCDBoot

BCDBoot copies the boot files again and creates a clean BCD from the existing Windows installation. This is very useful when the BCD is broken or BOOTMGR is missing.

1. From WinRE > Command Prompt, go to the drive where Windows is (for example, C:).
2. Run: BCDBoot C:\Windows

What exactly does it do?: BCDBoot (located in %WINDIR%\System32) uses the %WINDIR%\System32\Config\BCD-Template template to create a new BCD store y copy a minimal set of boot files to the system partition. Supports Windows Vista/7/8/8.1/10/Server 2008/2008 R2 images.

Using a bootable USB and partitioning software to repair the MBR

If you do not have the installation disc or prefer an alternative route, there are partitioning tools that allow you to create a USB WinPE with boot repair utilities.

1. On another working PC Create the media: Open the utility, choose “Boot Media” and generate the WinPE USB.
2. Boot the affected computer from that USB, access the disk tools and run the function Rebuild/Fix MBR.

Advantage: You can repair MBR/BCD even when you don’t have the Windows installer at hand. If you get stuckMany of these suites offer assistance to guide you.

Enter the pre-installed recovery options (without external media)

Some devices come with recovery pre-installed accessible with F8 in Windows 7 or from the manufacturer's own menus.

1. Remove any USB, CD or DVD and restart the PC.
2. Press F8 repeatedly before the Windows logo appears to open “Advanced startup options.”
3. Choose "Repair your computer", select the keyboard language and, if prompted, log in with your user.
4. In "Options of system recovery», opens Startup repair or if it doesn't work, go to Symbol of the system to use Bootrec/BCDBoot.

ImportantIf you don’t see “Repair your computer,” your model may not include these options or they may be disabled by your administrator.

Restore the boot sector and try System Restore

If the problem occurs after recent changes or updates, recovering a restore point can be a miracle cure.

1. Enter WinRE and go to Troubleshoot > Advanced Options > System Restore.
2. Select a previous point when the error appears and follow the wizard until it finishes.

Also, rewrite the boot sector with bootrec /fixboot from the console may be sufficient if it was damaged on its own. After the message "The operation completed successfully" appears, turn it off and back on.

Reset the BIOS to default values ​​and update its firmware

A misconfigured or outdated BIOS can prevent booting.. Two useful actions:

• Reset the BIOS to factory settings from its mode (Load Setup Defaults) and reset the boot order.
• Update the BIOS/UEFI to the latest version from the manufacturer: download the firmware to a USB, enter the update menu (often shown as “Flash”), and follow the process indicated by your board.

Warning: An improperly performed BIOS update can render your computer inoperable; follow the manufacturer's instructions exactly.

OEM Options: Factory Restore on Branded Equipment

Some manufacturers (e.g. VAIO) integrate recovery utilities to return the C: drive to its factory state from your Recovery Center.

1. Access the manufacturer's recovery environment and locate the option restore C drive: to its original condition.
2. Follow the wizard specific to your model (refer to the manufacturer's manual and support website).

WARNING: this option delete apps, settings, and data from the restored drive. Use this as a last resort or after making a backup.

When nothing works: Clean install of Windows

If after all the above the error persists, reinstalling Windows may be the fastest way. Use the installation media, choose the system partition and proceed. The partition will be formatted, but Quick formatting allows data recovery with specialized tools if you act quickly.

Recover files after fixing the boot (or before reinstalling)

If the origin was bad sectors or system corruption, you may have lost files. And if you reinstall, you'll also want to recover data. To do this, use a third-party recovery tool with deep analysis engine and preview.

1. Install the recovery software on a different disk than the affected one (so as not to overwrite).
2. Scan the drive/partition with the option “Search for lost data” or equivalent.
3. Check the items found, use filters by type (images, videos, documents) and the preview to verify.
4. Select and retrieve to a different drive. Some programs allow you to recover up to 500 MB free on Windows.

CouncilIf the drive is noisy or physically failing, avoid forcing reads; consider professional services to maximize the likelihood of success.

Quick Start Guide: Repair with Windows Installation Disc/USB

If you have the installation media, these are the shortcuts to the key options we have seen:

1. Boot from CD/DVD or USB and press a key when you see “Press any key to boot from CD or DVD.”
2. Select language, keyboard and press Next, then click Repair equipment.
3. Choose your Windows installation and enters Startup repair or open the Symbol of the system to run:
   • bootrec / fixmbr
   • bootrec / fixboot
   • bootrec / RebuildBcd
   • BCDBoot C:\Windows
   • chkdsk / f (if there are disk errors)
4. Exit with exit and restart to try.

If the PC does not detect the media automatically, enter BIOS/UEFI, set the boot order To put the USB/DVD first, save (F10) and try again.

Notes and good practices to prevent it from happening again

A couple of habits greatly reduce the likelihood of seeing BOOTMGR is missing again.:

• Regular backups in the cloud and on a local drive.
• UPS and updated antivirus to mitigate power surges and malware.
• Keep BIOS/UEFI and Windows up to date and avoid randomly disconnecting drives.

With this complete walkthrough—from checking cables and boot order to repairing with Bootrec/BCDBoot, using automatic repair, resorting to OEM options, or, if necessary, reinstalling and recovering data—you should be able to bring your Windows back to life when you see “BOOTMGR is missing.”Take it slow, try things a little bit more, and check after each step; one of these steps will usually resolve the problem.