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According to my research, I found that the directory of BCD for BIOS is System Reserved partition\boot\BCD, but in my system there is a similar directory [EFI\boot\] which does not contain the BCD file.

Why does the said directory and BCD do not exist for me?

JW0914
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SEPEHR
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1 Answers1

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The BCD Store file provides a store used to describe boot applications and settings.

EFI boot still has a BCD Store file, located in in the same place, just in a different top-end hierarchy (without a BCD Store file, Windows can't boot):

  • BIOS: \\<boot partition>\boot\BCD
  • EFI: \\<efi partition>\EFI\Microsoft\Boot\BCD
    \\<efi partition>\EFI\Microsoft\Recovery\BCD

The BCD Store file is managed with three utilities: BcdEdit, BcdBoot, and BootRec

Overview of Boot Options in Windows

Boot Configuration Data [BCD] Store:

Windows boot options are stored in the Boot Configuration Data [BCD] store on BIOS-based and EFI-based computers.

BCD provides a common, firmware-independent boot option interface, is more secure than previous boot option storage configurations, and lets Administrators assign rights for managing boot options; BCD is available at run time and during all phases of system setup.

You can manage BCD remotely and manage BCD when the system boots from media other than the media on which the BCD store resides. This feature can be used for debugging and troubleshooting, especially when a BCD store must be restored while running Startup Repair, from USB-based storage media, or even remotely.

The BCD store, with its object-and-element architecture, uses GUIDs and names such as default to identify boot-related applications, and BCD includes its own set of boot options. For more information about these boot options, see:
BCD Boot Options Reference


BCD System Store Settings for UEFI

Windows Boot Loader Settings:

A BCD store has at least one instance, and optionally multiple instances, of the Windows Boot Loader, with a separate BCD object representing each instance. Each instance loads one of the installed versions of Windows that has a configuration the object's elements have specified. Each Windows Boot Loader object has its own identifier, and the object's device and path settings indicate the correct partition and boot application.

BCD-template for a single Windows Boot Loader object:

## Windows Boot Loader

identifier              {9f25ee7a-e7b7-11db-94b5-f7e662935912}
device                  partition=C:
path                    \Windows\system32\winload.efi
description             Microsoft Windows Server
locale                  en-US
inherit                 {bootloadersettings}
osdevice                partition=C:
systemroot              \Windows


The identifier for this Windows Boot Loader is as follows, and you can use this GUID on your system, or let the BCDEdit tool generate a new GUID for you:
{9f25ee7a-e7b7-11db-94b5-f7e662935912}

To simplify BCDEdit commands, you can specify one of the Windows Boot Loaders in the BCD system store as the default loader, then use the standard identifier {default} in place of the full GUID.

This example specifies the Windows Boot Loader for EFI as the default boot loader, and assumes it uses the identifier GUID from BCD-template:

Bcdedit /default {9f25ee7a-e7b7-11db-94b5-f7e662935912}
JW0914
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