How to Fix Corrupt BCD in Windows 10: Step-by-Step Guide to Solve Boot Errors

When your Windows 10 computer fails to start properly, the problem might be a corrupt Boot Configuration Data (BCD). The BCD is a crucial file that tells your system how to boot. If it gets damaged, you can encounter boot errors that stop Windows from loading.

Fixing a corrupt BCD might seem technical, but it can be done step-by-step with simple tools built into Windows. This guide will walk you through the process in easy-to-understand steps.

By following these instructions carefully, you can repair your BCD and get your PC back to normal without losing your personal data.

Let’s begin by understanding some important checks before diving into the repair process.

Quick Note: Prerequisites and Initial Checks

Backup Important Data: If possible, back up your files using a recovery drive or connecting your hard drive to another computer. Repairing the BCD usually does not affect files, but it’s best to be safe.
Have Windows 10 Installation Media Ready: You will need a USB or DVD with Windows 10 setup to access recovery tools. If you don’t have one, you can create it using Microsoft’s Media Creation Tool on another PC.
Check for Hardware Issues: Sometimes boot errors are caused by faulty hardware like a failing hard drive. If possible, run quick diagnostics on your hard drive before proceeding.
Know Your System Type: Check if your Windows installation uses UEFI or Legacy BIOS. This can affect some repair commands. Most modern PCs use UEFI.

Step 1: Boot Into Windows Recovery Environment (WinRE)

To fix the BCD, you need to access recovery tools outside of Windows. Here’s how you can do that:

Insert your Windows 10 installation USB or DVD and restart your computer.
Press the key to open the boot menu (usually F12, Esc, or Del) immediately after powering on.
Select your USB or DVD drive to boot from the installation media.
When the Windows Setup screen appears, choose your language and preferences, then click Next.
Click on Repair your computer at the bottom left corner.
Choose Troubleshoot > Advanced options > Command Prompt.

This will open a command prompt window where you can enter commands to repair the BCD.

Step 2: Backup Existing BCD (Optional but Recommended)

Before making any changes, it’s wise to save a copy of your current BCD file in case you need to restore it later.

ren C:BootBCD BCD.bak

Explanation: This command renames the current BCD file to BCD.bak, effectively backing it up.

Note: If your Windows is installed on a drive other than C:, replace C: with the correct drive letter.

Step 3: Rebuild the BCD Store

Now, you will create a new BCD store that Windows can use to boot properly.

bootrec /rebuildbcd

This command scans all drives for Windows installations and allows you to add them to the new BCD store.

After running the command, you might see a message like:

“Total identified Windows installations: 1. Add installation to boot list? Yes/No/All:”

Type Y and press Enter to add the detected Windows installation.

Step 4: Repair the Master Boot Record (MBR) and Boot Sector

Sometimes the boot sector or MBR can also be damaged. Running these commands fixes those issues:

bootrec /fixmbr
bootrec /fixboot

What they do:

/fixmbr writes a new Master Boot Record to the system partition.
/fixboot writes a new boot sector to the system partition.

If you get an “Access Denied” error when running bootrec /fixboot, try this command to repair the EFI system partition (only for UEFI systems):

bootsect /nt60 sys

Step 5: Restart Your PC

Once the above commands complete successfully, close the Command Prompt window and choose Continue to exit and boot into Windows.

If Windows boots normally, your BCD was repaired successfully.

Alternative Method: Using bcdedit to Manually Repair BCD

If the automatic rebuild doesn’t work, you can use bcdedit to manually recreate the BCD store:

In Command Prompt, type the following to export the current BCD (if it exists):

bcdedit /export C:BCD_Backup

Delete the current BCD file:

attrib C:bootbcd -h -r -s
del C:bootbcd

Rebuild it using bootrec:

bootrec /rebuildbcd

This method gives you more control but requires caution.

FAQs

Q: What causes BCD corruption?

A: Common causes include sudden power loss, malware infections, failed Windows updates, or disk errors.

Q: Will fixing BCD delete my files?

A: No, repairing BCD only affects boot configuration data, not your personal files.

Q: Can I fix BCD without installation media?

A: It’s difficult because recovery tools are needed. If you can’t boot into Windows, installation media or a recovery drive is usually essential.

Q: What if I get “Access Denied” when running repair commands?

A: This often happens on UEFI systems. Try using bootsect /nt60 sys or ensure you are running Command Prompt as an administrator within WinRE.

Q: Is there a way to automate BCD repair?

A: Some third-party tools claim to automate BCD repair, but using Windows built-in tools is safest.

When Nothing Works

If none of the above steps fix the boot problem, you might consider these options:

System Restore: Use the System Restore feature from the recovery menu to revert Windows to a previous working state.
Reset This PC: This option reinstalls Windows while allowing you to keep your personal files.
Contact Microsoft Support: Visit the official Microsoft Support website for further help.
Professional Help: If hardware issues are suspected, consult a technician.

Conclusion

Corrupt BCD files can cause frustrating boot errors in Windows 10, but with the right steps, you can fix them yourself. Starting with simple recovery options and moving to rebuilding the BCD store helps ensure you don’t miss any easy fixes.

Always prepare by having installation media and backing up data if possible. Using the built-in Windows tools carefully will often restore your system’s ability to boot without needing advanced interventions.

By following this guide, you can confidently troubleshoot and resolve BCD corruption issues and get your Windows 10 PC running smoothly again.