By Ailsa / Last Updated November 26, 2020

What is BOOTMGR?

BOOTMGR is a file named Windows Boot Manager. The BOOTMGR can read the Boot Configuration Data (BCD) and execute the winload.exe, then the winload.exe will load the essential drivers to help your system start. It was first introduced in Windows Vista to replace the NTLDR boot manager in previous versions of Windows like Windows XP.

In most cases, the BOOTMGR file is located on System Reserved partition, if you don’t have a System Reserved partition, the file must be located on your system partition typically the C drive. In addition, you should be aware that the BOOTMGR file is read-only, and cannot be modified.

What is the cause of Bootmgr is missing?

We found that many many users look for help in the forums like that “Today I turn up my Sony laptop and try to boot from Windows 7, but it’s failed. An error message displayed ‘BOOTMGR is missing press Crl+Alt+Del to restart’ instead, I have no idea what happened; I just installed some widgets on my desktop yesterday. What should I do? Any help would be appreciated.”

BOOTMGR Is Missing

Besides, there are some other similar error messages like “Couldn’t find BOOTMGR”, “BOOTMGR is missing press any key to restart”. So, what causes such boot error messages? There are several reasons listed below for these BOOTMGR errors.

  • You are trying to boot computer from the external USB flash drive and there is no BOOTMGR file on that device.

  • The boot sector or MBR on your system may be damaged or missing.

  • The BIOS on your computer is outdated.

  • Hardware upgrades issues.

BOOTMGR Is Missing: How to Fix?

To fix BOOTMGR is missing errors in Windows 7/8/10, we’ll provide a variety of solutions to help you out. You can try them one by one until the error message disapper and the system start successfully.

Solution 1.Disconnect all external devices

Disconnect the external storage device, like USB flash drive, floppy disk or external hard drive, etc. If such like devices aren’t bootable, you will get the BOOTMGR is missing error.

Solution 2. Check the first boot device

If your system hard disk isn’t the first boot device, you computer will boot from other hard disk where has no boot files, then you’ll receive this error message definitely. Please make sure the right hard drive is listed the first place in the BIOS boot order.

Solution 3. Upgrade BIOS version

An out-dated BIOS may result in the error message. Please upgrade motherboard’s BIOS. Please make in mind for your current BIOS version and download the new version from the manufacturer website, if you have anything problem, please consult your manufacturer.

Solution 4. Repair Boot Sector

In order to repair your boot sector, you need a Windows Installation disc. Get into the start-up options, select “Repair your computer”, then you’ll get a list of Windows systems installed on your PC, choose the Windows you want to repair. You can fix the corrupted boot sector afterwards.

Repair Your Computer Windows 10

Solution 5. Rebuild MBR

The “BOOTMGR is missing” error message occurred to your computer probably due to the corrupted MBR. Thus, you can rebuild MBR for your computer. For this task, you can use the Windows installation disk and enter WinPE mode to rebuild it via Command Prompt, or directly use a professional MBR repair tool. See more details below and choose a proper method based on your situation.

5.1. Repair MBR with Command Prompt

The first thing you have to prepare is a Windows Installation disc. Then boot from that disc and enter system recovery options or repair your computer, and choose command prompt. Next you can enter these commands in turn.

  • bootrec /fixmbr

  • bootrec /fixboot

  • bootrec /scanos

  • bootrec /rebuildbcd

Fix Mbr

5.2. Rebuild MBR with AOMEI Partition Assistant

If you don’t keep the original Windows installation media any longer, or running such commands is complicated, you can use the powerful MBR repair tool: AOMEI Partition Assistant Professional. It comes with the “Rebuild MBR” feature to help Windows users fix the corrupted MBR. Before trying to fix the “BOOTMGR is missing” error with the feature, you need to create a bootable media via the software. The specific steps are listed below:

Try Free Demo Win 10/8.1/8/7/XP
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Step 1. (Download AOMEI Partition Assistant Pro demo version). Install and launch the software on another working computer. Connect an empty USB drive to it. On the main console, click “Make Bootable Media” and follow the subsequent prompts to make a bootable USB drive.

Make Bootable Media

Step 2. Connect the bootable USB device (it will contain the pre-installed AOMEI Partition Assistant Professional) to the computer with “BOOTMGR is missing” error and boot computer it.

Step 3. Once booting into the system, the AOMEI Partition Assistant software will be running automatically. Select the system hard disk and choose “Rebuild MBR” at the drop down menu.

Rebuild System Disk Mbr

Step 4. Select the MBR type for your Windows system, and hit “OK”.

Choose Mbr Type Os

Step 5. Click “Apply” > "Proceed" to rebuild MBR.


Solution 6. Check errors for Your System Hard Drive

Another cause of this error message could be the bad sector on your system hard drive. To test your hard drive whether has an error on it or not, you can use the previous AOMEI Partition Assistant Professional, too.

Step 1. Run AOMEI Partition Assistant, on the main window, right click on the system hard disk and choose “Surface Test” at the drop down menu.

Surface Test Os

Step 2. Click “Start” to test errors.

Quick Check Os

Tip: you can tick “Quick Check” to test quickly. Press “Cancel” when the operation is done.

In addition, you could run “chkdsk c:\ /f /r” as well to check for errors.

With the help of AOMEI Partition Assistant, you can easily fix “BOOTMGR is missing” problem. Besides, if the error still exists, your hard disk must be damaged and you have to replace it with another one. Please backup your system hard disk to another one with “Disk Clone” feature.