BCDBoot Command-Line Options

BCDBoot is a command-line tool used to configure the boot files on a PC or device to run the Windows operating system. You can use the tool in the following scenarios:

• Add boot files to a PC after applying a new Windows image. In a typical image-based Windows deployment, use BCDBoot to set up the firmware and system partition to boot to your image. To learn more, see Capture and Apply Windows, System, and Recovery Partitions.
• Set up the PC to boot to a virtual hard disk (VHD) file that includes a Windows image. To learn more, see Boot to VHD (Native Boot): Add a Virtual Hard Disk to the Boot Menu.
• Repair the system partition. If the system partition has been corrupted, you can use BCDBoot to recreate the system partition files by using new copies of these files from the Windows partition.
• Set up or repair the boot menu on a dual-boot PC. If you’ve installed more than one copy of Windows on a PC, you can use BCDBoot to add or repair the boot menu.

File Locations

In Windows and Windows Preinstallation Environment (WinPE)

In the Windows Assessment and Deployment Kit (WindowsВ ADK):

C:\Program Files (x86)\Windows Kits\10\Assessment and Deployment Kit\Deployment Tools\amd64\BCDBoot\BCDBoot.exe

Supported operating systems

BCDBoot can copy boot environment files from images of WindowsВ 10, Windows 8.1, WindowsВ 8, WindowsВ 7, WindowsВ Vista, Windows ServerВ 2016 Technical Preview, WindowsВ Server 2012 R2, Windows ServerВ 2012, Windows ServerВ 2008В R2, or WindowsВ ServerВ 2008.

How It Works

To configure the system partition, BCDBoot copies a small set of boot-environment files from the installed Windows image to the system partition.

BCDBoot can create a Boot Configuration Data (BCD) store on the system partition using the latest version of the Windows files:

• BCDBoot creates a new BCD store and initialize the BCD boot-environment files on the system partition, including the Windows Boot Manager, using the %WINDIR%\System32\Config\BCD-Template file.
• New in WindowsВ 10: During an upgrade, BCDBoot preserves any other existing boot entries, such as debugsettings, when creating the new store. Use the /c option to ignore the old settings and start fresh with a new BCD store.
• If there is already a boot entry for this Windows partition, by default, BCDBoot erases the old boot entry and its values. Use the /m option to retain the values from an existing boot entry when you update the system files.
• By default, BCDBoot moves the boot entry for the selected Windows partition to the top of the Windows Boot Manager boot order. Use the /d option to preserve the existing boot order.

On UEFI PCs, BCDBoot can update the firmware entries in the device’s NVRAM:

• BCDBoot adds a firmware entry in the NVRAM to point to the Windows Boot Manager. By default, this entry is placed as the first item in the boot list. Use the /p option to preserve the existing UEFI boot order. Use /addlast to add it to the bottom of the boot order list.

Command-Line Options

The following command-line options are available for BCDBoot.exe.

BCDBOOT [/l ] [/s [/f ]] [/v] [/m [<OS Loader GUID>]] [/addlast or /p] [/d] [/c]

Required. Specifies the location of the Windows directory to use as the source for copying boot-environment files.

The following example initializes the system partition by using BCD files from the C:\Windows folder:

Optional. Specifies the locale. The default is US English ( en-us ).

The following example sets the default BCD locale to Japanese:

Optional. Specifies the volume letter of the system partition. This option should not be used in typical deployment scenarios.

Use this setting to specify a system partition when you are configuring a drive that will be booted on another computer, such as a USB flash drive or a secondary hard drive.

UEFI:

BCDBoot copies the boot files to either the EFI system partition, or the partition specified by the /s option.

BCDBoot creates the BCD store in the same partition.

By default, BCDBoot creates a Windows Boot Manager entry in the NVRAM on the firmware to identify the boot files on the system partition. If the /s option is used, then this entry is not created. Instead, BCDBoot relies on the default firmware settings to identify the boot files on the system partition. By the UEFI 2.3.1 spec, the default firmware settings should open the file: \efi\boot\bootx64.efi in the EFI System Partition (ESP).

BIOS:

BCDBoot copies the boot files to either the active partition on the primary hard drive, or the partition specified by the /s option.

BCDBoot creates the BCD store in the same partition.

The following example copies BCD files from the C:\Windows folder to a system partition on a secondary hard drive that will be booted on another computer. The system partition on the secondary drive was assigned the volume letter S:

The following example creates boot entries on a USB flash drive with the volume letter S, including boot files to support either a UEFI-based or a BIOS-based computer:

Optional. Specifies the firmware type. Valid values include UEFI , BIOS , and ALL .

On BIOS/MBR-based systems, the default value is BIOS . This option creates the \Boot directory on the system partition and copies all required boot-environment files to this directory.

On UEFI/GPT-based systems, the default value is UEFI . This option creates the \Efi\Microsoft\Boot directory and copies all required boot-environment files to this directory.

When you specify the ALL value, BCDBoot creates both the \Boot and the \Efi\Microsoft\Boot directories, and copies all required boot-environment files for BIOS and UEFI to these directories.

If you specify the /f option, you must also specify the /s option to identify the volume letter of the system partition.

The following example copies BCD files that support booting on either a UEFI-based or a BIOS-based computer from the C:\Windows folder to a USB flash drive that was assigned the volume letter S:

Optional. Enables verbose mode. Example:

Optional. Merges the values from an existing boot entry into a new boot entry.

By default, this option merges only global objects. If you specify an OS Loader GUID, this option merges the loader object in the system template to produce a bootable entry.

The following example merges the operating-system loader in the current BCD store that the specified GUID identifies in the new BCD store:

Optional. Specifies that the Windows Boot Manager firmware entry should be added last. The default behavior is to add it first. Cannot be used with /p.

Optional. Specifies that the existing Windows Boot Manager firmware entry position should be preserved in the UEFI boot order. If entry does not exist, a new entry is added in the first position. Cannot be used with /addlast.

By default, during an upgrade BCDBoot moves the Windows Boot Manager to be the first entry in the UEFI boot order.

Optional. Preserves the existing default operating system entry in the object in Windows Boot Manager.

Optional. Specifies that any existing BCD elements should not be migrated.

New for WindowsВ 10: By default, during an upgrade, BCD elements such as debugsettings or flightsigning are preserved.

Repair the system partition

If the system partition has been corrupted, you can use BCDBoot to recreate the system partition files by using new copies of these files from the Windows partition.

Boot your PC to a command line. For example, boot to the Windows installation disk and press Shift+F10, or boot to Windows PE (WinPE: Create USB Bootable drive).

Use Diskpart to determine which drive letter contains your Windows partition and system partition ( diskpart, list vol, exit ).

Optional: Format your system partition: format (drive letter of your system partition) /q

Add a boot entry for your Windows partition: bcdboot D:\Windows

Reboot the PC. Windows should appear.

Set up or repair the boot menu on a dual-boot PC

When setting up a PC to boot more than one operating system, you may sometimes lose the ability to boot into one of the operating systems. The BCDBoot option allows you to quickly add boot options for a Windows-based operating system. To set up a dual-boot PC:

Install a separate hard drive or prepare a separate partition for each operating system.

Install the operating systems. For example, if your PC has WindowsВ 7, install WindowsВ 10 onto the other hard drive or partition.

Reboot the PC. The boot menus should appear with both operating systems listed.

If both operating systems aren’t listed:

Open a command line, either as an administrator from inside Windows, or by booting to a command line using the Windows installation media and pressing Shift+F10, or by booting to Windows PE (WinPE: Create USB Bootable drive).

Add boot options for a Windows operating system.

Reboot the PC. Now, the boot menu will show both menu options.

Troubleshooting

For information about repairing the boot files on a PC with Windows XP and a more recent version of Windows such as WindowsВ 7, see the Microsoft Knowledge Base Article 2277998.

Advanced troubleshooting for Windows boot problems

This article is intended for use by support agents and IT professionals. If you’re looking for more general information about recovery options, see Recovery options in Windows 10.

Summary

There are several reasons why a Windows-based computer may have problems during startup. To troubleshoot boot problems, first determine in which of the following phases the computer gets stuck:

Option	Description

Phase	Boot Process	BIOS	UEFI
1	PreBoot	MBR/PBR (Bootstrap Code)	UEFI Firmware
2	Windows Boot Manager	%SystemDrive%\bootmgr	\EFI\Microsoft\Boot\bootmgfw.efi
3	Windows OS Loader	%SystemRoot%\system32\winload.exe	%SystemRoot%\system32\winload.efi
4	Windows NT OS Kernel	%SystemRoot%\system32\ntoskrnl.exe

1. PreBoot

The PC’s firmware initiates a Power-On Self Test (POST) and loads firmware settings. This pre-boot process ends when a valid system disk is detected. Firmware reads the master boot record (MBR), and then starts Windows Boot Manager.

2. Windows Boot Manager

Windows Boot Manager finds and starts the Windows loader (Winload.exe) on the Windows boot partition.

3. Windows operating system loader

Essential drivers required to start the Windows kernel are loaded and the kernel starts to run.

4. Windows NT OS Kernel

The kernel loads into memory the system registry hive and additional drivers that are marked as BOOT_START.

The kernel passes control to the session manager process (Smss.exe) which initializes the system session, and loads and starts the devices and drivers that are not marked BOOT_START.

Here is a summary of the boot sequence, what will be seen on the display, and typical boot problems at that point in the sequence. Before starting troubleshooting, you have to understand the outline of the boot process and display status to ensure that the issue is properly identified at the beginning of the engagement.

Click to enlarge

Each phase has a different approach to troubleshooting. This article provides troubleshooting techniques for problems that occur during the first three phases.

If the computer repeatedly boots to the recovery options, run the following command at a command prompt to break the cycle:

Bcdedit /set recoveryenabled no

If the F8 options don’t work, run the following command:

Bcdedit /set bootmenupolicy legacy

BIOS phase

To determine whether the system has passed the BIOS phase, follow these steps:

1. If there are any external peripherals connected to the computer, disconnect them.
2. Check whether the hard disk drive light on the physical computer is working. If it is not working, this indicates that the startup process is stuck at the BIOS phase.
3. Press the NumLock key to see whether the indicator light toggles on and off. If it does not, this indicates that the startup process is stuck at BIOS.

If the system is stuck at the BIOS phase, there may be a hardware problem.

Boot loader phase

If the screen is completely black except for a blinking cursor, or if you receive one of the following error codes, this indicates that the boot process is stuck in the Boot Loader phase:

• Boot Configuration Data (BCD) missing or corrupted
• Boot file or MBR corrupted
• Operating system Missing
• Boot sector missing or corrupted
• Bootmgr missing or corrupted
• Unable to boot due to system hive missing or corrupted

To troubleshoot this problem, use Windows installation media to start the computer, press Shift+F10 for a command prompt, and then use any of the following methods.

Method 1: Startup Repair tool

The Startup Repair tool automatically fixes many common problems. The tool also lets you quickly diagnose and repair more complex startup problems. When the computer detects a startup problem, the computer starts the Startup Repair tool. When the tool starts, it performs diagnostics. These diagnostics include analyzing startup log files to determine the cause of the problem. When the Startup Repair tool determines the cause, the tool tries to fix the problem automatically.

To do this, follow theseВ steps.

For additional methods to start WinRE, see Windows Recovery Environment (Windows RE).

Start the system to the installation media for the installed version of Windows. For more information, see Create installation media for Windows.

On the Install Windows screen, select Next > Repair your computer.

On the System Recovery Options screen, select Next > Command Prompt.

After Startup Repair, select Shutdown, then turn on your PC to see if Windows can boot properly.

The Startup Repair tool generates a log file to help you understand the startup problems and the repairs that were made. You can find the log file in the following location:

%windir%\System32\LogFiles\Srt\Srttrail.txt

Method 2: Repair Boot Codes

To repair boot codes, run the following command:

To repair the boot sector, run the following command:

Running BOOTREC together with Fixmbr overwrites only the master boot code. If the corruption in the MBR affects the partition table, running Fixmbr may not fix the problem.

Method 3: Fix BCD errors

If you receive BCD-related errors, follow these steps:

Scan for all the systems that are installed. To do this, run the following command:

Restart the computer to check whether the problem is fixed.

If the problem is not fixed, run the following command:

You might receive one of the following outputs:

If the output shows windows installation: 0, run the following commands:

After you run the command, you receive the following output:

1. Try restarting the system.

Method 4: Replace Bootmgr

If methods 1, 2 and 3 do not fix the problem, replace the Bootmgr file from drive C to the System Reserved partition. To do this, follow these steps:

At a command prompt, change the directory to the System Reserved partition.

Run the attrib command to unhide the file:

Run the same attrib command on the Windows (system drive):

Rename the Bootmgr file as Bootmgr.old:

Navigate to the system drive.

Copy the Bootmgr file, and then paste it to the System Reserved partition.

Restart the computer.

Method 5: Restore System Hive

If Windows cannot load the system registry hive into memory, you must restore the system hive. To do this, use the Windows Recovery Environment or use Emergency Repair Disk (ERD) to copy the files from the C:\Windows\System32\config\RegBack to C:\Windows\System32\config.

If the problem persists, you may want to restore the system state backup to an alternative location, and then retrieve the registry hives to be replaced.

Starting in Windows 10, version 1803, Windows no longer automatically backs up the system registry to the RegBack folder.This change is by design, and is intended to help reduce the overall disk footprint size of Windows. To recover a system with a corrupt registry hive, Microsoft recommends that you use a system restore point. For more details, check this article.

Kernel Phase

If the system gets stuck during the kernel phase, you experience multiple symptoms or receive multiple error messages. These include, but are not limited to, the following:

A Stop error appears after the splash screen (Windows Logo screen).

Specific error code is displayed. For example, «0x00000C2» , «0x0000007B» , «inaccessible boot device» and so on.

The screen is stuck at the «spinning wheel» (rolling dots) «system busy» icon.

A black screen appears after the splash screen.

To troubleshoot these problems, try the following recovery boot options one at a time.

Scenario 1: Try to start the computer in Safe mode or Last Known Good Configuration

On the Advanced Boot Options screen, try to start the computer in Safe Mode or Safe Mode with Networking. If either of these options works, use Event Viewer to help identify and diagnose the cause of the boot problem. To view events that are recorded in the event logs, follow these steps:

Use one of the following methods to open Event Viewer:

Click Start, point to Administrative Tools, and then click Event Viewer.

Start the Event Viewer snap-in in Microsoft Management Console (MMC).

In the console tree, expand Event Viewer, and then click the log that you want to view. For example, click System log or Application log.

In the details pane, double-click the event that you want to view.

On the Edit menu, click Copy, open a new document in the program in which you want to paste the event (for example, Microsoft Word), and then click Paste.

Use the Up Arrow or Down Arrow keyВ to view the descriptionВ of the previous or next event.

Clean boot

To troubleshoot problems that affect services, do a clean boot by using System Configuration (msconfig). Select Selective startup to test the services one at a time to determine which one is causing the problem. If you cannot find the cause, try including system services. However, in most cases, the problematic service is third-party.

Disable any service that you find to be faulty, and try to start the computer again by selecting Normal startup.

If the computer starts in Disable Driver Signature mode, start the computer in Disable Driver Signature Enforcement mode, and then follow the steps that are documented in the following article to determine which drivers or files require driver signature enforcement: Troubleshooting boot problem caused byВ missing driver signature (x64)

If the computer is a domain controller, try Directory Services Restore mode (DSRM).

This method is an important step if you encounter Stop error «0xC00002E1» or «0xC00002E2»

Examples

Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall the operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

Error code INACCESSIBLE_BOOT_DEVICE (STOP 0x7B)

To troubleshoot this Stop error, follow these steps to filter the drivers:

Go to Window Recovery Environment (WinRE) by putting an ISO disk of the system in the disk drive. The ISO should be of same version of Windows or a later version.

Open the registry.

Load the system hive, and name it as «test.»

Under the following registry subkey, check for lower filter and upper filter items for Non-Microsoft Drivers:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Control\Class

For each third-party driver that you locate, click the upper or lower filter, and then delete the value data.

Search through the whole registry for similar items. Process as an appropriate, and then unload the registry hive.

Restart the server in Normal mode.

For additional troubleshooting steps, see the following articles:

To fix problems that occur after you install Windows updates, check for pending updates by using these steps:

Open a Command Prompt window in WinRE.

Run the command:

If there are any pending updates, uninstall them by running the following commands:

Try to start the computer.

If the computer does not start, follow these steps:

Open A Command Prompt window in WinRE, and start a text editor, such as Notepad.

Navigate to the system drive, and search for windows\winsxs\pending.xml.

If the Pending.xml file is found, rename the file as Pending.xml.old.

Open the registry, and then load the component hive in HKEY_LOCAL_MACHINE as a test.

Highlight the loaded test hive, and then search for the pendingxmlidentifier value.

If the pendingxmlidentifier value exists, delete the value.

Unload the test hive.

Load the system hive, name it as «test».

Navigate to the following subkey:

HKEY_LOCAL_MACHINE\SYSTEM\ControlSet001\Services\TrustedInstaller

Change the Start value from 1 to 4

Unload the hive.

Try to start the computer.

If the Stop error occurs late in the startup process, or if the Stop error is still being generated, you can capture a memory dump. A good memory dump can help determine the root cause of the Stop error. For details, see the following articles:

For more information about page file problems in Windows 10 or Windows Server 2016, see the following:

For more information about Stop errors, see the following Knowledge Base article:

If the dump file shows an error that is related to a driver (for example, windows\system32\drivers\stcvsm.sys is missing or corrupted), follow these guidelines:

Check the functionality that is provided by the driver. If the driver is a third-party boot driver, make sure that you understand what it does.

If the driver is not important and has no dependencies, load the system hive, and then disable the driver.

If the stop error indicates system file corruption, run the system file checker in offline mode.

To do this, open WinRE, open a command prompt, and then run the following command:

If there is disk corruption, run the check disk command:

If the Stop error indicates general registry corruption, or if you believe that new drivers or services were installed, follow these steps:

1. Start WinRE, and open a Command Prompt window.
2. Start a text editor, such as Notepad.
3. Navigate to C:\Windows\System32\Config.
4. Rename the all five hives by appending «.old» to the name.
5. Copy all the hives from the Regback folder, paste them in the Config folder, and then try to start the computer in Normal mode.