Another reason you might see BOOTMGR errors is if your PC is trying to boot from a hard drive or flash drive that is not properly configured to be booted from. In other words, it’s trying to boot from a non-bootable source (i.e., one that doesn’t contain proper boot files). This also would apply to media on an optical drive or floppy drive that you’re trying to boot from.
BOOTMGR Errors
There are few ways that the “BOOTMGR is missing” error may show up on your computer, with the first error listed here being the most common:
BOOTMGR is missing Press Ctrl Alt Del to restartBOOTMGR is missing Press any key to restartCouldn’t find BOOTMGR
The “BOOTMGR is missing” error displays shortly after the computer is turned on, immediately after the Power On Self Test (POST) is complete. Windows has only initially started to load when the BOOTMGR error message appears.
How to Fix ‘BOOTMGR Is Missing’ Errors
We sort of hit on this in the troubleshooting step above, but it’s important to call out specifically that you might have the wrong hard drive listed since many BIOS/UEFI systems allow you to specify a particular hard drive to be booted from first. Try replacing the PATA or SATA cable if you suspect it might be faulty. Even though a Startup Repair is a common solution for BOOTMGR problems, don’t worry if it doesn’t fix your problem. Just continue troubleshooting—something will work. The partition boot sector is an important piece in the boot process, so if there’s any issue with it, you’ll see problems like “BOOTMGR is Missing” errors. If you can’t gain access to your files to back them up, please understand that you will lose them all if you continue with a clean installation of Windows!
