bootmgr

I have a laptop  that has a bootmgr  missing how can I repair it

Rebuild the boot configuration data (BCD) from Windows Recovery Environment (WinRE).

1. In the System Recovery Options dialog box, click Command Prompt.

2. Type Bootrec /RebuildBcd command and then press ENTER.

You can also run System Restore tool from Windows Recovery Environment (WinRE).