Fix Bootmgr is missing Press Ctrl+Alt+Del to restart on Windows 10, 8, 7 | Windows101Tricks | Scoop.it
From howtofixwindows.com - December 17, 2017 3:04 PM

Getting boot manager is missing Press Ctrl+Alt+Del to restart error on Windows 10, 8, 7 computer ? Boot from installation media to access advanced options then perform startup repair and rebuild BOOTMGR by perform command Bootrec /fixMbr, Bootrec /fixBoot, Bootrec /ScanOS and Bootrec /RebuildBcd