Bdehdcfg command in Windows

The bdehdcfg command prepares a hard disk with the partitions needed for disk encryption with BitLocker. Most installations of Windows 7 will not need to use this tool because setting up BitLocker includes the ability to prepare and partition the required drive.

Warning:

There is a conflict with the installation of Group Policy Deny access to fixed drives not protected by BitLocker in Computer Configuration Administrative TemplatesWindows ComponentsBitLocker Drive EncryptionFixed Data Drives .

If Bdehdcfg is run on the computer when this policy setting is enabled, you may experience the following problems:

1. If you try to minimize the drive and create a system drive, the drive size will be successfully reduced and a raw partition will be created. However, the raw partition will not be formatted. The following error message is displayed: " The new active Drive cannot be formatted. You may need to manually prepare your drive for BitLocker. "
2. If you tried to use unallocated space to create a system drive, a rough partition will be created. However, the raw partition will not be formatted. The following error message is displayed: " The new active Drive cannot be formatted. You may need to manually prepare your drive for BitLocker. "
3. If you try to merge an existing drive to the system drive, the tool will not copy the required boot file to the target drive to create the system drive. The following error message is displayed: " BitLocker setup failed to copy boot files. You may need to manually prepare your drive for BitLocker. "

If this policy setting is being executed, a hard drive cannot be repartitioned because the drive is already protected. If you are upgrading your computer from the old Windows version and those computers are configured with a partition, you should create the required BitLocker system partition before applying policy settings to computers.

For an example of how to use this command, see Example .

Syntax

 merge}] [–newdriveletter] [-size] [-quiet] 

Parameters

ParametersDescription BDdddff: driveinfo Displays drive letters, total size, maximum free space and partitioning characteristics of partitions on the specified drive. Only valid partitions are listed. Unallocated space is not listed if 4 primary or extended partitions already exist. Bdehdcfg: target Determines which part of the drive is used as the system drive and makes that part work. Bdehdcfg: newdriveletter Assign a new drive letter to the drive section used as the system drive. Bdehdcfg: size Determine the size of the system partition, when the new system drive is being created. Bdehdcfg: quiet Prevent the display of all actions and errors in the command line interface and instruct Bdehdcfg to use the "Yes" answer for any Yes / No prompt that may occur during drive preparation. Next disk. Bdehdcfg: restart Guides the computer to restart after the drive preparation process ends. /? Show help at the command prompt.

For example

The following example describes Bdehdcfg being used with the default drive to create a 500MB system partition. Since no drive letter is specified, the new system partition will not have a drive letter.

 bdehdcfg -target default -size 500 

The following example describes Bdehdcfg being used with the default drive to create the system partition (P :), which has a default size of 300MB in the unallocated space on the drive. The tool will not prompt the user to enter any additional information, nor will it show any errors. After the system drive has been created, the computer will automatically restart.

 bdehdcfg -target unallocated –newdriveletter P: -quiet -restart 

See more:

1. Bitsadmin create command in Windows
2. Bitsadmin complete command in Windows
3. Bitsadmin cancel command in Windows