How to fix Boot BCD startup errors on Windows PCs
I was greeted by a Recovery error message the other day when I powered up a PC running Microsoft's Windows 10 operating system. The recovery screen stated that "Your PC/Device needs to be repaired. The Boot Configuration Data for your PC is missing or contains errors".
The PC shut down properly the day before and the whole thing was mysterious. The Recovery screen suggested to use recovery tools or contact a PC administrator or the PC/Device manufacturer for assistance.
Read on to find out how I repaired the PC and how you can do it as well.
Boot BCD startup errors
Boot problems related to the BCD come in many different forms. Here is a short list of error messages that Windows may throw during boot:
- Your PC/Device needs to be repaired. The Boot Configuration Data for your PC is missing or contains errors
- There was a problem with a device connected to your PC. An unexpected I/O error has occurred.
- Your PC needs to be repaired. The Boot Configuration Data file doesn't contain valid information for an operating system.
- Windows failed to start. A recent hardware or software change might be the cause.
One common denominator is that the Recovery screen references the file \boot\bcd.
Cause of BCD related startup errors
The error can be a result of (among other reasons):
- An unexpected shutdown.
- Bluescreen or other errors that require a restart.
- Data corruption.
- Failing hard drives.
- BCD file corruption or misconfiguration.
- Malicious software.
What is BCD?
Boot Configuration Data (BCD) was introduced in Windows Vista by Microsoft. It replaced the boot.ini file in Vista. The BCD holds important boot-related information including the list of the available operating systems.
In short, it stores vital boot information required to start Windows. If the BCD is missing, corrupt or altered, Windows may not start properly anymore but display the Recovery screen at the top.
Fixing BCD issues if you cannot boot
All issues described above have in common that you cannot boot into Windows anymore. You cannot use tools like the Visual BCD Editor to correct the issue on the affected machine because of that as you cannot boot into Windows anymore.
Generally speaking, it is required that you boot into the advanced startup (Windows 10 or 8.1) or system recovery options (Windows 7) and run several commands from the command prompt there.
If you do have Windows installation media, you can use it to boot from and access the recovery options.
Windows 10 users can download media from Microsoft instead.
Step by Step guide
- Insert the installation media into the PC. Connect the USB Flash Drive to the computer or put the DVD into the DVD drive.
- Find out how to access the BIOS/UEFI of the machine. This should be displayed during boot. Common keys are F1, F12 or DEL.
- Change the boot order so that the computer boots from the USB or DVD drive before it boots from internal hard drives.
- Click next on the first screen of setup. That screen should highlight the installation language and keyboard.
- Select Repair your computer on the next screen.
- When the "choose an option" menu opens, select Troubleshoot.
- Select Advanced options.
- Select Command Prompt. This opens a command prompt interface.
- Run the following commands one after the other:
- bootrec /fixmbr -- This option writes a MBR to the system partition but does not overwrite the system partition in the process. It fixes MBR corruption and issues with non-standard MBR code.
- bootrec /fixboot -- This options writes a new boot sector to the system partition. Fixes damaged boot sectors, non-standard boot sectors, and issues caused by the installation of earlier Windows operating systems (pre-Vista). Ignore any error that may come up.
- bootrec /rebuildbcd -- This options scans all connected hard drives for Windows installations. If it finds additional installations, prompts you to add them to the BCD Store. Windows should pick up the installed operating system. Make sure you add it to the BCD store. Select (a) for all during the prompt, or add installations individually instead.
- Exit the command prompt window.
- Restart the PC to find out if the repair was successful.