To fix BOOTMGR is missing in Windows 7 without CD, you can create a bootable USB from ISO and then boot the PC from the USB drive to enter the Windows Recovery Environment. Subsequently, question is, how do I restore Windows Boot Manager? Fix #1: Use bootrec
Here are the steps to fix the BOOTMGR error with an installation CD:
Similarly, it is asked, how do I fix Bootmgr is missing? You can repair it with the XP CD start the CD as if going to install Windows XP but select the first 'R' option to open the Recovery Console then use commands MBR FIX and Enter, then follow with FIXBOOT and hit Enter.