If you are seeing a BOOTMGR is missing error then you must be using either a Windows 7 operating system or Windows Vista. Earlier versions of Windows use NTLDR so in that case you might see an error message saying the NTLDR is missing.

Fixing the BOOTMGR is missing error also involves using different methods and commands and in this article we will examine these ways.

What Do BOOTMGR Error Messages Look Like?

When this error appears on your computer screen it is usually just after starting your computer. The computer has ran the  Power On Self Test (POST) and noticed that something is missing. It won’t boot into Windows if there is a BOOTMGR problem.

“BOOTMGR is missing
Press Ctrl Alt Del to restart”

“BOOTMGR is missing
Press any key to restart”

“Couldn’t find BOOTMGR”

What Causes a BOOTMGR Error?

1. Bootmgr is missing. Yes there just doesn’t seem to be a valid bootmgr on the hard drive you’re trying to boot to. It might exist but could be corrupt or not configured correctly. I have had a  damaged boot sector of a hard drive after not shutting down a computer correctly. That is how easy it is sometimes.

2. Malware often can change the boot sector files and can make them unreadable to enable boot.

3. It is common for a hard drive to fail as they never last as long as you think. If they are dead, they are dead.

4. Your hard drive has bad sectors and the bootloader files have been written to these bad sectors. You can try running Chkdsk by using the chkdsk /f command as it might be able to recover these sectors. But when this starts happening you can bet your hard drive is on it’s way out and it is time to replace it now. 

5. POST can’t find the BOOTMGR because the hard drive is not even plugged in. Maybe the cable is loose or faulty.

6. Your computer is trying to boot to another bootable device that is not configured correctly. For example, you have a bootable USB flash drive plugged in when you start your computer. 

7. Your BIOS settings are not set to go straight to the main hard drive so it goes through the bootable devices and get stuck. For example your BIOS settings might be configured to boot from a CD but the device might not be working or the CD in the device is not bootable. See how to change your BIOS settings.

Also see what is a boot sector and how does it work.

How To Troubleshoot BOOTMGR Errors

There are a number of causes for this problem so there are also a number of solutions that may or may not work for you. We will start with the most simple solutions and work our way down.

1. The first thing you should do in most cases is to restart the computer. You never know, the error might have been a temporary problem and sometimes restarting the system fixes all.

2. Check to see if you have any USB flash drives or external drives plugged in. They can easily cause problems when trying to boot your computer.

3. Check all internal cables, especially ones leading to bootable devices. Make sure they are not loose.

4. Unplug extra devices like additional hard drives and dvd drives. Then go into your BIOS and set it to boot to your hard drive first. This way we can see if your main harddrive is the problem because if it boots you know it is fine. If it doesn’t boot then there is a problem on the main drive. Plug the dvd back in to use for further troubleshooting.

5. Put your Windows operating system disc in the DVD and make sure your BIOS is set to start from this device first.

1. Place the Windows Vista or Windows 7 installation disc in the disc drive, and then start the computer.
2. Press a key when you are prompted.
3. Select a language, a time, a currency, a keyboard or an input method, and then click Next.
4. Click Repair your computer.
5. Click the operating system that you want to repair, and then click Next.

You want to run through Startup Repair (number one choice in the system recovery options list) where your files will be compared with ones on the disc and then replaced if needed. This is an automatic repair.

6. If that doesn’t work we need to start the windows operating system disc again but instead of choosing the first system recovery option we need to choose “command prompt”.  This is so we can enter some commands in manually to rebuild the boot configuration table.  See more instructions here.

7. If all else fails you can format the hard drive, create a new system partition and install a fresh copy of Windows on it. This means that you will loose all data from your hard drive so hopefully you have a backup ready.

8. If your HDD is not recognised at all and you can’t do any repairs, access it through an external device or even format the drive then it is possibly dead. Replace the harddrive and start from scratch. The reason I have put this solution last is because there are usually good signs that your hard drive is failing so a BOOTMGR error is most likely a software problem. If you do suspect a hardware problem please see these free hardware diagnostic tools.