Fix Boot BCD Error 0xc000000f on Windows

When Windows fails to start, it may display a black screen with the text: “Windows failed to start. A recent hardware or software change might be the cause. To fix the problem: Insert your Windows installation disc and restart your computer… File: \Boot\BCD Status: 0xc000000f”.

This error means the Boot Configuration Data (BCD) store is missing, corrupt, or inaccessible. The BCD is a database that tells the Windows boot manager which operating system to load and where its files are located. The boot manager reads this file early in the startup process; if it cannot read it, it stops with this error.

The error often appears after a failed Windows update, a disk partitioning error, a power outage during a write operation, or an attempt to dual-boot that went wrong. It can also occur when the firmware (BIOS/UEFI) is set to boot from the wrong device, or when the disk containing the BCD is not detected.

This guide walks through the most common causes and the repairs in order of least destructive first. Before starting, have a Windows installation media (USB or DVD) available, as most repairs require booting from it.

Understanding the BCD and the Error

The BCD store is a file (usually \Boot\BCD on the system partition) that contains boot entries. The boot manager (bootmgr) reads this file to know what to start. If the file is missing, corrupted, or the boot manager cannot access it, you get error 0xc000000f.

Common scenarios:

• Corrupted BCD: The file is present but unreadable. This can happen after a failed update or disk write error.
• Missing BCD: The file was deleted or the partition was reformatted.
• Wrong boot device: The firmware is set to boot from a device that does not contain a valid BCD (e.g., a USB drive or a second hard drive).
• Disk not recognized: The disk containing Windows is not visible to the boot manager due to a loose cable, failed drive, or incorrect SATA mode.

Diagnosing the Cause

Before attempting repairs, determine which scenario applies. This avoids wasting time and possibly making things worse.

Check the Boot Order in Firmware

Enter the firmware setup (usually by pressing Del, F2, F12, or Esc during startup) and check the boot order. Ensure the device containing Windows (the hard drive or SSD) is first. If a USB drive is plugged in, remove it and try again. Sometimes the firmware defaults to a different device after a BIOS update or CMOS reset.

Boot from Windows Installation Media

If the firmware is set correctly, boot from the Windows installation USB/DVD. Choose your language, then click “Repair your computer” instead of “Install now”. This gives access to recovery tools.

Use Command Prompt to Inspect the System

From the recovery environment, open Command Prompt (Troubleshoot > Advanced options > Command Prompt). The next two commands are diskpart commands, so start diskpart first:

diskpart
list disk

This lists all physical disks. Note the disk number for the one that contains Windows (usually Disk 0).

list volume

This lists all volumes. Look for the volume with the Windows installation (in the recovery environment it is often not C:, so note its letter) and the small system partition (usually 100-500 MB, often without a drive letter). On a UEFI PC that is the FAT32 EFI system partition, and the BCD is at \EFI\Microsoft\Boot\BCD; on a BIOS PC it is the active NTFS “System Reserved” partition, and the BCD is at \Boot\BCD. Type exit to leave diskpart.

If the disk or volume is not listed, the drive may be disconnected, powered off, or failed. Check cables and power connections. If the drive is not detected, the error is not a BCD problem but a hardware issue.

Repairing the BCD

Once you have confirmed the disk is present, attempt the following repairs in order.

1. Rebuild the BCD using bootrec

This is the first-line repair. It rebuilds the BCD from scratch using the Windows installation files.

bootrec /rebuildbcd

This scans all disks for Windows installations and asks to add them to the BCD. If it finds an installation, type Y and press Enter. After completion, reboot.

If the command reports “Total identified Windows installations: 0”, the BCD is not the only problem; the Windows partition may be missing or the disk may not have a valid installation.

2. Fix the Master Boot Record (MBR) or GUID Partition Table (GPT)

If the BCD is missing because the boot sector is damaged, fix it with:

bootrec /fixmbr

This writes new master boot record code to sector 0 of the disk; it applies to BIOS/MBR disks only and does nothing useful on a UEFI/GPT system. It does not change the partition table or data.

bootrec /fixboot

This writes a new boot sector to the system partition on a BIOS/MBR disk. On UEFI systems it commonly fails with “Access is denied”; use the bcdboot repair below instead.

These commands do not delete files. Run them in order, then try bootrec /rebuildbcd again.

3. Rebuild the Boot Files and BCD with bcdboot

If bootrec /rebuildbcd fails, rebuild the store with bcdboot, the tool Microsoft documents for repairing the system partition (BCDBoot Command-Line Options). It copies fresh boot files from the Windows folder and creates a new BCD; there is no need to build a store entry by entry with bcdedit.

Give the system partition a letter inside diskpart:

diskpart
list volume
select volume 1
assign letter=S
exit

Replace 1 with the number of the small system partition from list volume, and note the Windows volume letter (for example D:). Rename the old store, so a damaged BCD is not carried into the new one; on a UEFI PC:

ren S:\EFI\Microsoft\Boot\BCD BCD.old

On a BIOS PC the file is S:\Boot\BCD. If the file does not exist, the command fails harmlessly. Then rebuild, using /f UEFI on a UEFI PC or /f BIOS on a BIOS PC:

bcdboot D:\Windows /s S: /f UEFI

Replace D: with the Windows volume letter. bcdboot carries settings over from a store it finds on the partition, which is why the old one is renamed first. Do not create a store by hand and load it with bcdedit /import: /import replaces the entire system store. If the drive uses BitLocker, unlock it first with manage-bde -unlock D: -RecoveryPassword <key>, and expect to be asked for the recovery key at the next start.

4. Use Startup Repair

From the recovery environment, choose Startup Repair. This tool attempts to fix boot problems automatically, including BCD issues. It may take several minutes. It is less precise than manual commands but often works.

5. Check for Disk Errors

If the BCD is corrupted due to disk errors, run chkdsk on the Windows partition.

chkdsk C: /f /r

This scans for bad sectors and attempts recovery. It may take a long time. It does not delete data, but if the disk is failing, it may not help.

6. Reset the Firmware to Defaults

If the firmware boot order is wrong, resetting to defaults can help. In the firmware setup, look for “Load Optimized Defaults” or “Reset to Factory Defaults”. This does not affect data, but it may change other settings.

When the Disk is Fine and the Firmware is Wrong

A common mistake is assuming the BCD is corrupt when the firmware is simply booting the wrong device. This happens after a BIOS update, CMOS reset, or when multiple drives are present. The error appears because the boot manager cannot find the BCD on the selected device.

How to tell: If the disk with Windows is detected in the firmware but the boot order lists a different device first, that is the cause. Also, if you can boot from a Windows installation USB and see the Windows partition, the disk is fine.

Fix: Change the boot order to prioritize the correct drive. If the drive is not listed, check connections and SATA mode (AHCI vs IDE). In some cases, enabling Legacy Boot or disabling Secure Boot may be necessary, but only if the BCD is for a legacy installation.

Comparison of Repair Methods

Common Misdiagnosis: “The Hard Drive is Dead”

When error 0xc000000f appears, many assume the hard drive has failed. This is a natural assumption because the error is boot-related and the drive seems unresponsive. However, a dead drive usually produces a different symptom: the machine may not detect the drive at all, or you may hear clicking sounds. In many cases, the drive is fine; the BCD is simply corrupt or the firmware is misconfigured.

This misdiagnosis leads to unnecessary hardware replacement. Before concluding the drive is dead, check if the drive appears in the firmware or in the recovery environment. If it does, the drive is likely functional. Also, a drive that is failing may still be readable enough to repair the BCD, but if you suspect failure, back up data immediately.

Another common mistake is running bootrec /fixmbr on a UEFI system with GPT partitioning. This command is for BIOS/MBR systems; on UEFI, it may not help and could potentially cause issues. Always confirm the partition style before using MBR-specific commands.

What People Get Wrong About This Error

1. Assuming the BCD is always corrupt: Sometimes the error is due to a simple boot order issue. Always check firmware first.
2. Using third-party BCD repair tools: Many online guides recommend paid tools that claim to fix BCD automatically. These are unnecessary; the built-in commands are sufficient. Third-party tools may cause more harm.
3. Reinstalling Windows prematurely: Reinstalling should be the last resort. The repairs above solve most cases without data loss. Reinstallation wipes the system partition and may require data backup.
4. Ignoring disk health: If the BCD keeps corrupting, the disk may be failing. Run chkdsk and check SMART status.

Final Steps

If none of the above works, the Windows installation may be beyond repair. In that case, back up data from the recovery environment (if possible) and perform a clean installation. This will erase the system partition and reinstall Windows.

Remember to always have a backup of important data, as boot errors can sometimes be a sign of hardware failure.