Sometimes BOOTMGR is present but the BCD store is corrupt:
A: Your hard drive may have physical damage. Run chkdsk C: /f /r from the recovery command prompt. If bad sectors are found, the drive is failing. Replace the hard drive, then restore Windows 7 from a backup. windows 7 bootmgr download
To fix a missing BOOTMGR, you need to use a Windows 7 Installation disc or USB. Sometimes BOOTMGR is present but the BCD store
Microsoft provides direct links to download official Windows 7 Service Pack 1 (SP1) through their website. While this doesn't directly download Bootmgr, installing SP1 can often repair or update Boot Manager files. Replace the hard drive, then restore Windows 7 from a backup
Put the Windows 7 installation DVD or USB drive into your computer.
The BOOTMGR (Boot Manager) file is a hidden, read-only file located in the root directory of the partition set as "Active". Common reasons it goes missing include: