Fix Boot Configuration Data Missing Error 0xc0000034 on Windows 11

Your Windows PC won’t start and displays the Recovery screen with error code 0xc0000034 stating that the Boot Configuration Data (BCD) is missing or contains errors. This startup error usually means Windows cannot find the information required to start the operating system. The Boot Configuration Data (BCD) is a database that stores the boot settings and the location of your Windows installation. During startup, Windows Boot Manager reads this information to locate and start Windows.

If the BCD is missing or corrupted due to a failed Windows update, disk errors, an improper shutdown, or changes to disk partitions, Windows stops the startup process and displays error 0xc0000034. In this guide, you’ll learn what causes the Boot Configuration Data Missing Error 0xc0000034 and solutions to rebuild the boot configuration and restore Windows startup.

What Causes Error Code 0xc0000034?

Error code 0xc0000034 usually occurs when Windows cannot locate or read the Boot Configuration Data (BCD) required to start the operating system. The most common causes include:

• Corrupted or missing Boot Configuration Data (BCD): The BCD contains the boot information Windows Boot Manager needs to locate and start Windows.
• Failed or interrupted Windows Update: An incomplete update can damage the boot configuration or replace important startup files.
• Disk errors or bad sectors: File system corruption or bad sectors on the system drive can make the BCD inaccessible.
• Accidental changes to disk partitions: Deleting, resizing, or modifying the EFI System Partition or System Reserved Partition can remove or damage the boot files.
• Replacing or cloning an SSD/HDD: Migrating Windows to a new drive without updating the boot configuration may result in a missing BCD.
• Incorrect BIOS/UEFI settings: Changing the boot mode (UEFI/Legacy) or boot order can prevent Windows Boot Manager from finding the correct boot files.
• Failing storage drive: A failing SSD or hard drive may no longer be able to read the files required during startup.

Before You Begin: Try These Quick Checks

Before repairing the Boot Configuration Data (BCD), try these basic checks. They only take a few minutes and may resolve error 0xc0000034 without further troubleshooting.

• Disconnect all unnecessary external devices, including USB flash drives, external hard drives, memory cards, and DVDs.
• Restart your PC and check if Windows boots normally.
• If you recently installed or replaced an SSD or hard drive, make sure it is properly connected and detected in the BIOS/UEFI.
• If you recently changed BIOS/UEFI settings, restore the default settings or verify that Windows Boot Manager is the first boot option.

If the error still appears, continue with the solutions below.

Method 1: Rebuild the Boot Configuration Data (BCD)

Since error code 0xc0000034 indicates that the Boot Configuration Data (BCD) is missing or contains errors, rebuilding the BCD is the most effective solution to try first. This process scans your computer for installed Windows operating systems and creates a new boot configuration, allowing Windows Boot Manager to locate and start Windows correctly.

To rebuild the Boot Configuration Data:

• Boot into the Windows Recovery Environment (WinRE). If your PC can’t enter WinRE automatically, use a Windows 11 installation USB and select Repair your computer. (Learn how to access WinRE.)

• Select Troubleshoot > Advanced options > Command Prompt.

• Run the following commands one at a time, pressing Enter after each command:

bootrec /fixmbr
bootrec /fixboot
bootrec /scanos
bootrec /rebuildbcd

• If Windows detects an installation, type Y to add it to the boot list.
• Close the Command Prompt and restart your computer.

If bootrec /fixboot Returns “Access is denied”

On some UEFI-based Windows 11 systems, the bootrec /fixboot command may display an “Access is denied” message. If this happens, skip that command and continue with the remaining ones. If Windows still fails to boot, proceed to the next method to recreate the Windows boot files using the BCDBOOT command.

After restarting, check whether Windows starts normally. If error 0xc0000034 still appears, continue with the next solution.

Method 2: Restore Windows Boot Manager Using BCDBOOT

If the Boot Configuration Data (BCD) has been repaired but Windows still displays error 0xc0000034, the Windows boot files stored in the EFI System Partition may be missing or damaged. The BCDBOOT tool copies fresh boot files from your Windows installation and recreates Windows Boot Manager, allowing your PC to boot normally again.

To restore Windows Boot Manager:

• Boot into the Windows Recovery Environment (WinRE) and open Command Prompt.
• Run the following command:

bcdboot C:\Windows

• Press Enter and wait for the command to complete.
• If the command completes successfully, restart your computer and check whether Windows starts normally.

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

If BCDBOOT reports an error

If you receive an error such as “Failure when attempting to copy boot files”, Windows may be unable to access the EFI System Partition. This can happen if the partition is damaged or missing. Continue with the remaining methods below to verify your boot settings and repair any underlying disk or system file issues.

Method 3: Verify Windows Boot Manager Is the Default Boot Option

Even after repairing the Boot Configuration Data (BCD) and restoring the Windows boot files, error 0xc0000034 can still occur if your computer is trying to boot from the wrong device. This may happen after resetting the BIOS, updating the firmware, replacing a storage drive, or connecting multiple drives.

Check the boot settings

1. Restart your PC and enter the BIOS/UEFI setup by pressing the appropriate key during startup (such as F2, Delete, Esc, or F10, depending on your computer manufacturer).
2. Open the Boot menu.
3. Make sure Windows Boot Manager is listed as the first boot option.
4. Confirm that your Windows SSD or hard drive is detected.
5. Verify that the boot mode matches your Windows installation:
   • UEFI for most Windows 11 systems.
   • Legacy/CSM only if Windows was originally installed in Legacy BIOS mode.
6. Save the changes and restart your computer.

If Windows Boot Manager is missing from the boot menu or your system drive isn’t detected, the problem may be related to the EFI partition or the storage drive itself. Continue with the next method to check the drive for file system errors.

Method 4: Scan the System Drive for File System Errors

The Boot Configuration Data (BCD) is stored on your system drive. If the drive contains file system errors or bad sectors, Windows may be unable to read the BCD correctly, resulting in error 0xc0000034. Running CHKDSK scans the drive for errors and repairs problems that could prevent Windows from starting.

To scan the drive:

1. Open Command Prompt from the Windows Recovery Environment (WinRE).
2. Run the following command:

chkdsk C: /f /r

3. Press Enter and wait for the scan to finish. Depending on your drive size and the number of errors found, this process may take some time.
4. Restart your computer after the scan completes.

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

If CHKDSK repairs errors, try restarting Windows. If it reports a large number of bad sectors or repeatedly finds new errors, your SSD or hard drive may be failing and should be backed up and replaced as soon as possible.

Method 5: Let Windows automatically repair startup files

If you’ve already repaired the Boot Configuration Data (BCD) and restored the Windows boot files but error 0xc0000034 still appears, use Startup Repair to check for any remaining startup issues. This built-in recovery tool scans the boot process and automatically repairs common problems that may prevent Windows from loading.

To run Startup Repair:

1. Boot into the Windows Recovery Environment (WinRE).
2. Select Troubleshoot > Advanced options > Startup Repair.
3. Choose your Windows installation if prompted.
4. Wait while Windows scans your PC and attempts to automatically repair startup problems.
5. Restart your computer after the repair completes.

If Startup Repair reports it couldn’t repair your PC, or error 0xc0000034 persists, proceed to the next method to check for corrupted Windows system files.

Method 6: Repair Corrupted Windows System Files

If the boot configuration has been repaired but Windows still won’t start, corrupted or missing system files may be preventing the operating system from loading correctly. The System File Checker (SFC) and Deployment Image Servicing and Management (DISM) tools can scan your Windows installation and replace damaged system files.

Run the System File Checker (SFC)

1. Open Command Prompt from the Windows Recovery Environment (WinRE).
2. Run the following command:

sfc /scannow /offbootdir=C:\ /offwindir=C:\Windows

3. Wait for the scan to complete. If SFC detects corrupted files, it will attempt to repair them automatically.

Repair the Windows Image with DISM

If SFC cannot repair all system files, run:

DISM /Image:C:\ /Cleanup-Image /RestoreHealth

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

Restart your computer after both scans complete and check whether Windows starts normally.

Method 7: Restore Windows Using System Restore

If error 0xc0000034 started after installing a Windows update, driver, or software, restoring your PC to an earlier restore point may resolve the problem. System Restore reverts Windows system files, drivers, and registry settings to a previous working state without affecting your personal files.

Note: This method only works if System Restore was enabled before the startup error occurred.

To restore your PC:

• Boot into the Windows Recovery Environment (WinRE).
• Select Troubleshoot > Advanced options > System Restore.

• Choose your Windows account and enter the password if prompted.
• Select a restore point created before error 0xc0000034 started appearing.
• Click Next > Finish and wait for Windows to restore your system.
• Restart your computer after the restoration process completes.

If Windows still won’t start or no restore points are available, proceed to the final method.

Method 8: Reset Windows as a Last Resort

If none of the previous methods resolve error 0xc0000034, your Windows installation may be too damaged to repair. In this case, resetting Windows can reinstall the operating system and replace corrupted boot and system files.

To reset your PC:

• Boot into the Windows Recovery Environment (WinRE).
• Select Troubleshoot > Reset this PC.

• Choose one of the following options:
  • Keep my files: Reinstalls Windows while preserving your personal files, but removes installed apps and resets system settings.
  • Remove everything: Erases your files, apps, and settings before reinstalling Windows.
• Follow the on-screen instructions to complete the reset process.

If Reset this PC doesn’t resolve the problem, the startup error may be caused by severe disk corruption or a failing SSD/HDD. In that case, back up your data if possible and perform a clean installation of Windows 11 using a bootable USB drive.

Frequently Asked Questions