What is Bootmgr and how it works?
Bootmgr can read the Boot Configuration Data (BCD) is the Windows boot sequence manager first introduced in Microsoft Vista to replace the NTLDR boot manager in previous versions of Windows. Bootmgr reads boot configuration data and displays the operating system selection menu NTLDR, Operating system terms.
1 What is Bootmgr and how it works?2 Fix Bootmgr is Missing in Windows 102.1 Remove all connected media2.2 Check boot order in BIOS2.3 Perform a Startup Repair of windows2.4 Rebuild the Boot Configuration Data2.5 Make Windows Partition Active2.6 Repair Windows Image
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. And the main work of this Bootmgr is to control boot volume and help you when a computer starts to load pre-installed windows. Or we can say, bootmgr is fully responsible for starting your computer’s Operating System.
Fix Bootmgr is Missing in Windows 10
If your computer won’t turn on or boot due to bootmgr missing error, here we have a few useful solutions apply to fix the issue of Boot Manager missing on windows 11 or 10. Sometimes BOOTMGR error messages could be caused by unplugged, loose, or malfunctioning power or controller cables. Again sometimes replacing the SATA or PATA cable fix the issue as well.
Remove all connected media
If you plug any external media like USB Drive or external HDD, your BIOS may probably trying to boot from the external device instead of the correct boot volume. Thus please remove all the connected media to your PC, and reboot your computer.
Check boot order in BIOS
If After removing all the connected media, BOOTMGR is missing error may still exist, Then you need to check boot order in BIOS. If the wrong drive is listed first, you could see BOOTMGR errors and you need to change and make sure the correct hard drive or other bootable device is listed first. To do this Press Ctrl+Alt+Del to restart your computer. While bootup windows or the manufacturer’s logo pops up, keep pressing the specific key(commonly it is F12) to get into BIOS. NOTE: The key to get into BIOS can be F2, F8, F10,F12, Esc or Del, etc. If you are not sure, consult the manufacturer of your computer.
Here move to the boot Tab using the left and right Arrow keys.Now Under the Boot tab, use ↑ or ↓ key to highlight your correct boot hard drive.Then use + or – key to move your boot drive onto the top to be the first boot device.
After making changes Press F10 on the keyboard to save settings and exit BIOS. Then your PC will restart automatically, now check if it could boot into your operating system successfully. If not, try the next solution.
Perform a Startup Repair of windows
Windows have an inbuild Automatic repair tool that checks and fixes all startup Errors which prevent windows to start normally. Before performing any troubleshooting steps we recommend first to perform the startup repair. Hence windows won’t boot normally, we need an installation media to access advanced troubleshooting options and perform startup repair. You can read our guide on how to create a bootable USB drive with Windows.
First, insert the windows installation media into your computer and reboot,Press Del key or F2 key to access BIOS, here change the first boot with your installation media,Press F10 to save and exit BISO, now press any key to boot from installation media,Next Select your language preferences and click Next and now Click Repair your computer in the bottom-left.
This will restart windows and on the next screen On Choose an option screen, click Troubleshoot and then click Advanced option. This will display all available Tools as shown below image.
Now click on Startup Repair. This will restart the windows and start the repair process. During the repair process, this will check below points.
Missing/corrupt/incompatible driversMissing/corrupt system filesMissing/corrupt boot configuration settingsCorrupt registry settingsCorrupt disk metadata (master boot record, partition table, or boot sector)Problematic update installation
Wait until the Windows Automatic/Startup Repair is complete. After that Restart and you have successfully fix BOOTMGR is missing error. Still getting the same error follow the next step.
Rebuild the Boot Configuration Data
It’s possible that your boot files got corrupted by some recently installed Software, Viruses, Windows or Software updates and it’s better to get it to repair as soon as possible. This data can be rebuilt using a few commands, Access advanced options and select the command prompt form there.
When the Command Prompt window opens, type bootrec /RebuildBcd and press Enter. In addition, run the following commands as well. Bootrec /fixmbr Bootrec /fixbootbootrec /scanos
The above commands repair the bootmgr Errors. Now repair the hard disk for Errors by performing the bellow command. Chkdsk /f /r Type this command and hit enter key to repair hard disk errors and bad sectors. After completing the “chkdsk” command 100% completed, just restart your computer hope this time your windows start normally. If still the same error performs the next step.
Make Windows Partition Active
An active partition is a partition in your computer’s hard disk which is known as a bootable partition that actually contains your PC’s Operating System. Normally, only one partition can be active at a time like C: drive, mostly where our windows is installed. But sometimes that partition got inactive due to some reasons Reactive partition can mostly fix most Boot Errors include bootmgr missing. Let’s See How to reactive First, you need to Access Windows Advanced Boot options. Here you will get the option to Open Advanced Command. prompt. When the command prompt opens type bellow commands diskpart This command will start the disk part utility in your command prompt. When diskpart will start you’ll be able to see “DISKPART>” sign on the left side of your command prompt. list disk This will list all of your connected drives on your computer. select disk 0 Note: Select the Hard Disk Drive where your windows is installed. In My cause, I am selecting Disk 0 because that’s the only disk drive shown in my CMD and that’s also the one where my OS is actually installed. list partition This command will show you all the partitions created in that disk that you’ve selected. select partition 2 Normally we are selecting partition 2 because that’s our windows partition but that does not prove that you will always need to select the 2nd one because sometimes partition 1 can be our windows partition too. So, select only that partition where your windows is installed. Note: Never Select 100 MB, 350 MB And 500 MB Partitions. active That will make your partition active.
Repair Windows Image
After performing the above methods Still, if the problem is not solved then repairing the windows image may fix windows startup problems including bootmgr missing. You can do this by following the first Open Command Prompt and enter the following command: DISM /Online /Cleanup-Image /RestoreHealth Press enter to run the above command and wait for the process to complete, usually, it takes 15-20 minutes. NOTE: if the above command doesn’t work then try this: Dism /Image:C:\offline /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows Dism /Online /Cleanup-Image /RestoreHealth /Source:c:\test\mount\windows /LimitAccess After the process is completed restart your PC Check the problem is solved. If none of the steps mentioned above fixed the “Bootmgr is missing” error, your hard drive itself could potentially be the issue, in which case it should be replaced. These are some best working solutions to fix Bootmgr missing startup Errors on Windows 10 or 11 computers permanently. Have any query suggestions feel free to comment below. Also read:
How to Repair or rebuild Master Boot Record (MBR) on Windows 10/8.1How to repair missing or corrupted system files windows 10Solved: No Text displayed in explorer after Windows 10 updateFix Pin to Start Missing From Context Menu In Windows 10EaseUS Partition Master: Best Partition Manager for Windows PC
