BOOTMGR Is Missing? Fix It Easily in Windows 7/8/10/11

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 the 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.”

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

BOOTMGR is missing: How to fix it?

To fix BOOTMGR's missing errors in Windows 7/8/10/11, we’ll provide various solutions to help you out. You can try them one by one until the error message disappear and the system starts successfully.

• Solution 1. Disconnect all external devices

• Solution 2. Check the first boot device

• Solution 3. Upgrade BIOS version

• Solution 4. Repair Boot Sector

• Solution 5. Rebuild MBR

• Solution 6. Check errors for Your System Hard Drive

Solution 1. Disconnect all external devices

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

Solution 2. Check the first boot device

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

Solution 3. Upgrade BIOS version

An outdated BIOS may result in an error message. Please upgrade the motherboard’s BIOS. Please make in mind your current BIOS version and download the new version from the manufacturer's website, if you have anything problems, please consult your manufacturer.

Solution 4. Repair Boot Sector

To repair your boot sector, you need a Windows Installation disc.

Step 1. 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 afterward.

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

▶ 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 bootable media via the software. The specific steps are listed below:

Step 1. (Download the AOMEI Partition Assistant Pro demo version). Install and launch the software on another working computer. Connect an empty USB drive to it. On the central console, click "Tools" and select “Make Bootable Media” and follow the subsequent prompts to make a bootable USB drive.

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

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

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

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, click "Test" and choose “Disk Surface Test” at the drop-down menu.

Step 2. Click “Start” to test errors.

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

To sum up

With the help of AOMEI Partition Assistant, you can easily fix the “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 back up your system hard disk to another one with the “Disk Clone” feature. If it's too late to back up, you can try the "Recover Data" function to retrieve lost data.