The latest versions of Windows, including windows Vista, and windows 7, use Boot Manager for Windows to read the boot configuration files to load the Windows desktop.
If either of these files is corrupted or deleted, you will see the error “BOOTMGR is missing” translate as “BOOTMGR file deleted or corrupted”. Fortunately, you can use a number of windows tools to repair or replace the Bootmgr file or any file that is associated with it, which can be the cause of the problem with loading windows.
Insert the Windows installation disk of the computer and restart the computer using Ctrl + Alt + Del or the button on the “restart” case.
Press “F8” many times until the computer boots. This command takes you to the “alternative boot options” screen.
Select the option “Restore my computer”, and then press “Enter”. The System Restore Options screen appears.
Select the option “Restore the download of windows” at the top of the list and click “Next”. The utility pro scans your system for the cause of the Bootmgr problem and repairs it.15 January 2016