Windows Boot Manager, abbreviated as BOOTMGR is a small piece of software that initiates the Windows boot sequence.
Bootmgr is loaded from the volume boot record. It executes winload.exe (Windows boot loader) with the purpose to load essential device drivers and a core part of the Windows operating system.
Bootmgr was introduced in Windows Vista which Microsoft released to the public on January 30, 2007. In previous versions of Windows, that's before Vista; a program referred to as NTLDR was the boot manager. This means that Windows XP users won't get the bootmgr is missing error.
Bootmgr is essential for the boot sequence to begin; without it, the operating system will not load. In other words, if ‘Bootmgr is missing’ then your computer won't boot. In this post, we discuss how to fix ‘Windows Bootmgr is missing’ errors in Windows.
The Bootmgr is missing error message may show up in the following way:
The first error in the list is the most common. The ‘Bootmgr’ is missing error shows up shortly after you hit the power button, as soon as the POST (Power On Self-Test) is complete.
The error in Windows can be as a result of:
Option 1: Restarting your PC
The Bootmgr is missing error could just have been an unlikely occurrence. A simple action like restarting can resolve the error. It is always a good idea to start with this simple solution, as you won't modify any system settings or spend time investigating the issue if a simple reboot fixes it.
Option 2: Check all the external storage media, and change Boot Order
It can happen that the PC attempts to boot from a different device, for instance when you have inserted a DVD or USB Flash drive, and the PC is configured to prioritize those over internal hard drives.
These external storage media includes optical drives, flash drives, external hard disks, and floppy disks.
It can happen after you connected a Flash drive or external hard drive to your PC, or after you added a new internal hard drive to it.
If your PC attempts to boot from a non-bootable storage media, then the "BOOTMGR is missing" error will be displayed.
If you find this to be the cause of the error, then try changing the boot order in BIOS such that the hard drive is listed first.
Else, always be ready to remove the external storage media every time you want to turn on your PC (and connect it afterwards to use it). This option is not really that practical, and it is recommended to change the boot order instead in most cases.
Option 3: Check all the internal data and power cables
Bootmgr is missing error could be caused by loose, malfunctioning or unplugged controller or power cables. Maybe the hard disk cables are hanging loose or are not connected properly to the motherboard anymore.
You need to open the PC case for this. Make sure the PC is powered off, and the power supply is cut. Open the case and check the cables of the hard drives to make sure they are properly connected.
This can happen if you have moved the PC recently for instance, or after unpacking it for the first time when it was delivered to you.
Option 4: Run System Restore or Startup Repair from a Windows Recovery Environment (WinRE)
This method requires a Windows installation disc or a bootable flash drive, or a preinstalled recovery option; for System Restore to work, it had to be enabled prior to running the recovery tools.
Follow these steps to enter Windows RE:
This process will try to restore the damaged or missing bootmgr files either by restoring a previous system snapshot using System Restore, or by attempting to fix startup issues.
Option 5: Rebuilding Boot Configuration Data from Windows RE
Another option that you have is to rebuild BCD (Boot Configuration Data) using a Windows Recovery Environment.
This method requires a Windows installation disc or flash drive. The steps are nearly the same as under 4, so follow them until you are in the System Recovery Options.
You may try the following bootrec commands as well:
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