author avatar
22 August 2024  Ashley S. Miller  Specialist of Customer Service Dept.
 

Summary
The Boot Configuration Data (BCD) Store file is essential for the Windows operating system's boot process and is located in the System Reserved partition, which is often hidden and lacks a drive letter. Accessing this file directly is challenging because the OS keeps it open, but you can use the BCDEDIT tool with administrative privileges to create a backup copy for examination.



Table of contents

table iconThe BCD Editor
table iconCommands in BCDEDIT
table iconBCD Editor Examples
table iconBCD File Experiments
table iconHow to Rebuild BCD in Windows
table iconUsing Renee Becca for System Migration to avoid BCD errors
table iconConclusion
The Boot Configuration Data (BCD) Store file is a crucial component in the Windows operating system’s boot process. This file is typically found in the Boot folder of a Windows 7, 8.1, or 10 operating system’s System Reserved partition. In many cases, this partition does not have a drive letter assigned, making it invisible in standard file explorers. To access it, you’ll need to assign a drive letter through Disk Management and adjust the Folder Settings to show hidden system files.

However, even with these adjustments, the BCD file remains inaccessible as it is kept open by the OS. Instead, you can use the BCDEDIT program to create a backup copy of the BCD file, which can then be examined using a hex editor or Notepad.

Insight of Operating System booting process – Windows 10 – AN IT DIARY of AI, Windows, MEM & PowerShell
If you need to upgrade to a new Western Digital(WD) and would like to deal with the boot record in BCD seamlessly and smoothly, please refer to How to Use Western Digital Cloning Software For Windows 10/11.

The BCD Editor

To use the BCDEDIT tool, you need to run the Command Prompt with Administrator privileges. Simply entering “bcdedit” in a standard Command Prompt will result in an “Access is denied” error.
How to dual boot Windows 7 and Windows XP using BCD Configuration Database | Interface Technical Training
Upon running the Command Prompt as an administrator, you can see the typical output of the “bcdedit” command:

bcdedit

The BCD Editor allows you to modify the boot configuration data store, which controls how the operating system is booted. This data was previously stored in the Boot.ini file for BIOS-based systems or in nonvolatile RAM for EFI-based systems. The BCDEDIT tool provides various commands to manipulate the BCD store, such as creating, deleting, and exporting entries.

Commands in BCDEDIT

Commands that operate on a store

/createstore

Creates a new and empty boot configuration data store.

/export

Exports the contents of the system store to a file.

/import

Restores the state of the system store using a backup file.

Commands that operate on entries in a store

/copy

Makes copies of entries in the store.

/create

Creates new entries in the store.

/delete

Deletes entries from the store.

Commands that operate on entry options

/deletevalue

Deletes entry options from the store.

/set

Sets entry option values in the store.

Commands that control output

/enum

Lists entries in the store.

/v

Displays entry identifiers in full.

Commands that control the boot manager

/bootsequence

Sets the one-time boot sequence for the boot manager.

/default

Sets the default entry that the boot manager will use.

/displayorder

Sets the order in which the boot manager displays the multiboot menu.

/timeout

Sets the boot manager time-out value.

Commands that control Emergency Management Services

/bootems

Enables or disables Emergency Management Services for a boot application.

/ems

Enables or disables Emergency Management Services for an operating system entry.

/emssettings

Sets the global Emergency Management Services parameters.

Commands that control debugging

/bootdebug

Enables or disables boot debugging for a boot application.

/dbgsettings

Sets the global debugger parameters.

/debug

Enables or disables kernel debugging for an operating system entry.

Commands that control remote event logging

/eventsettings

Sets the global remote event logging parameters.

/event

Enables or disables remote event logging for an operating system entry.

BCD Editor Examples

For instance, to export the system store to a file, you can use:

C:\>bcdedit /export "C:\bcdtemp.bin"

Upon examining this backup file with a hex editor, it becomes evident that the BCD file contains much more information than the old boot.ini file. The first 4 bytes “regf” indicate that the BCD file uses the same format as a Windows Registry hive. This is why the BCD file is more complex and contains what appears to be ‘gunk’.
hex Code of BCD

BCD File Experiments

Changing the NT Disk Signature

If you alter the NT Disk Signature in the MBR, the system will fail to boot, displaying a black error screen with Status: 0xc000000e.
Error Screen
Restoring the original NT Disk Signature will allow the system to boot again. This error can also occur if the system attempts to boot from a different drive with a mismatched BCD store.

Moving the C: Volume

Attempting to move the C: Volume under Windows 7 or later results in a similar error with Status: 0xc0000225. This issue arises because the BCD file does not contain the sector location of the C: drive, making it difficult to relocate the partition without causing boot errors.
If you want to migrate your Windows 7/8/10/11 to a new drive, please try to use Renee Becca.

How to Rebuild BCD in Windows

If the BCD becomes corrupt, you may encounter errors like Error code: 0xc0000098. To rebuild the BCD, you can use the following commands:

BOOTREC /SCANOS


BOOTREC /FIXMBR


BOOTREC /FIXBOOT


BOOTREC /REBUILDBCD

Rebuild BCD
If access is denied for /fixboot, you may need to explore other methods to rebuild the BCD.
Error Screen

Using Renee Becca for System Migration to avoid BCD errors

Renee Becca is a tool specifically designed for system and hard disk data backup and restoration. It can efficiently back up and restore essential data on your computer, including programs, system configurations, emails, photos, videos, documents, and bookmarks. Additionally, it allows for disk and system data cloning with 3 different cloning methods: hard disk cloning, partition cloning, and system migration. Choose the most suitable method based on your individual needs.
Hot Topic - ADsRenee Becca – Safe and Quick System Migration to SSD

Automatic 4K alignment Improves SSD performance during system migration.

Support GPT and MBR Automatically adapt to the suitable partition format.

Support NTFS and FAT32 Redeploy various files in different file systems.

Back up quickly Back up files at up to 3,000MB/min.

Overall backup schedule Support system redeployment/system backup/partition backup/disk backup/disk clone.

Automatic 4K alignment Improve SSD performance

Support GPT and MBR Intelligently adapt to a partition format

Support NTFS and FAT32 Redeploy files in different file systems

Free TrialFree TrialNow 2000 people have downloaded!
With the help of Renee Becca, it is very convenient to migrate the Windows 10 system to the hard disk of other computers, making it a system disk. The specific steps are as follows:
Step 1: Connect the hard disk of other computers to the original computer through an external hard disk box. Download and install Renee Becca on the original computer, and select the “System Redeploy” option in the main interface under the “Clone” column.
connect disk to another computer with enclosure
select system redeploy function in clone
Step 2: In the “System Migration” window, choose a new hard disk as the target location and the system partition as the source. Click the migration button to start the process. Wait for the progress bar to reach 100% to indicate successful migration. Install the new hard disk on other computers and set it as the first boot device in the BIOS. Check and adjust the settings in the BIOS if needed.
select a destination to redeploy system with renee becca
Kind tips: The total capacity of the new hard disk needs to be greater than the size of the system to be migrated; in addition, since all data in the target disk will be erased during the system migration, please check whether the target disk exists before the official system migration. Important data, and make file backups in advance. If you want to migrate all the data of the original system hard disk (not just the system partition) to the new hard disk, you can also choose the hard disk clone/clone system hard disk) function.

Conclusion

The BCD Store file is a critical component in the Windows boot process, containing essential boot configuration data. Using the BCDEDIT tool, administrators can manipulate this data to troubleshoot and resolve boot issues. Understanding the structure and commands of the BCD Editor is vital for maintaining a healthy and bootable Windows system.
Hot Topic - ADsRenee Becca – Safe and Quick System Migration to SSD

Automatic 4K alignment Improves SSD performance during system migration.

Support GPT and MBR Automatically adapt to the suitable partition format.

Support NTFS and FAT32 Redeploy various files in different file systems.

Back up quickly Back up files at up to 3,000MB/min.

Overall backup schedule Support system redeployment/system backup/partition backup/disk backup/disk clone.

Automatic 4K alignment Improve SSD performance

Support GPT and MBR Intelligently adapt to a partition format

Support NTFS and FAT32 Redeploy files in different file systems

Free TrialFree TrialNow 2000 people have downloaded!