BCD or otherwise known as Boot Configuration Data contains boot configuration parameters on how to start your Windows. If the configuration file gets corrupted, you will have to rebuild BCD or Boot Configuration Data file. Usually, when BCD gets corrupted, it results in unbootable situations on Windows 10/8/7.
In earlier versions of Windows, the boot information was stored in the Boot.ini file. On EFI-based operating system, you’ll find the entry in the EFI firmware boot manager, which is available at- \EFI\Microsoft\Boot\Bootmgfw.efi.
Rebuild BCD in Windows 10
BCD or Boot Configuration Data is a firmware-independent database file which has boot-time configuration data. It is required by Windows Boot Manager and replaces the boot.ini that was used by NTLDR earlier. In the case of boot problems, you may be required to rebuild BCD.
- Boot your computer into Advanced Recovery Mode
- Launch Command Prompt available under Advanced Options.
- To rebuild the BCD or Boot Configuration Data file use the command – bootrec /rebuildbcd
- It will scan for other operating systems and let you select the OS’s you want to add to BCD.
If this does not help, you can manually set the boot path. However, do so only if you are an expert, as it could create issues.
In the Command Prompt, type the following command and hit Enter:
bcdboot c:\windows /s c:
The BCDboot tool is a command-line tool that enables you to manage system partition files. If the system partition has been corrupted, you can use BCDboot to replace the system partition files with new copies of these files from the Windows partition.
When you run this command, it will give you a new Bootloader. Here “c” is the System drive. You should only do this when you know the exact drive on which Windows was installed.
Lastly, we recommend you take a look at this post to how to repair & rebuild MBR or Master Boot Record. If you are not comfortable with the commands, then you can use third-party tools such as EasyBCD or Dual-Boot Repair to repair your BCD file.
Related reading: Windows 10 fails to boot; Automatic Startup Repair, Refresh, Reset PC also fails