This guide will help you troubleshoot the “BOOTMGR is missing” error, as well as provide possible solutions. This error is fairly common on Windows 7/10 and other.
Error notification regarding a missing boot manager in Windows may contain slightly different messages, like “Couldn’t find BOOTMGR” or “BOOTMGR is missing” and can be followed by a request to either press any key or to press the CTR + ALT + DEL key combination in order to continue. Either way, these are all just different variations of the same error. “BOTMGR is missing “errors usually appear shortly after you’ve started your machine, as soon as the Power On Self Test (POST) is over.
Sadly, there are numerous reasons for this error to occur and we cannot tell you exactly why it’s appearing in your specific case. The BOOTMGR is missing error could be caused by corrupt or badly configured files and hard drive sectors, an outdated BIOS, issues with a hard drive and/or operating system upgrade. The error might also be the result of loose or damaged hard drive interface cables. Alternatively, you may be faced with the said error message because your computer is trying to boot from a non-bootable source, like a hard or flash drive that wasn’t configured properly for this purpose.
However, no matter the exact reason, we will attempt to provide several fixes that could help you get this issue solved. Follow the instructions listed below and please don’t hesitate to let us know if you encountered problems on the way.
BOOTMGR is Missing Fix
Try rebooting your machine. It’s very possible that the error message was a fluke and a simple restart will solve the problem.
If the error persists, we suggest you check your USB ports, optical and floppy drives. It could be that your PC is trying to boot from a non-bootable source, as pointed out above.
If you find that your computer is indeed trying to boot from the wrong disc/drive, you will have to change the boot order in the BIOS, so that the correct source is listed first.
Check to see that all internal and data cables are seated firmly. In some cases, the error could be caused by a loose or unplugged cable, so be sure to adjust those if necessary and replace any faulty cables with new ones, should there be any.
If there are any missing or corrupt files that are causing the error, a Startup Repair of Windows should replace them. Perform one to see if it solves the issue.
In the event that none of the above did the trick for you, this solution will almost certainly work, however, it is a radical one. You might need to re-install your Windows from scratch, which will be sure to resolve any BOOTMGR issues.
Note: this is a time-consuming process and one that will wipe clean any data of yours. You will need to back-up all of your files, or else they will be lost for good.