We have previously read about the BitLocker feature, where we’ve mentioned about the
BitLocker Drive Preparation Tool. This tool is currently not available as a download for Windows 7 or Windows 8, and later users and only Windows Vista and Windows Server 2008 users can take benefit of it. But if you still want to use the abilities of this tool, then you can use command line tool. In this article, we will talk about using the BitLocker Drive Preparation Tool using Command Prompt in Windows 8.1.

Basically,
BitLocker Drive Preparation tool prepares a hard drive with the partitions necessary for
BitLocker Drive Encryption. Most installations of
Windows 7 or later recognize the command line tool. Here is how you can use it.
Using BitLocker Drive Preparation Tool via Command Prompt in Windows 8 / 7
1. In order to use
BitLocker Drive Preparation command line tool, open the administrative Command Prompt.
2. Next, you can use the following command with suitable descriptors mentioned below and press
Enter:
bdehdcfg [–driveinfo <DriveLetter>] [-target {default|unallocated|<DriveLetter> shrink|<DriveLetter> merge}] [–newdriveletter] [–size <SizeinMB>] [-quiet]The above mentioned command is in general form and its variable parameters can altered using following descriptors:
-driveinfo <DriveLetter>: Displays the drive letter, the total size, the maximum free space, and the partition characteristics. Only valid partitions are listed. Unallocated space is not listed if four primary or extended partitions already exist.
Example : To display information for C: drive, use bdehdcfg –driveinfo C: command.-target {default|unallocated|<DriveLetter> shrink|<DriveLetter> merge} : Prepares a partition for use as a system drive by BitLocker and Windows Recovery. By default, this partition is created without a drive letter.
Example : In order to use this command to designate an existing drive (K) as the system drive, use bdehdcfg -target K: merge at Command Prompt.
-newdriveletter : Assigns a new drive letter to the portion of a drive used as the system drive. As a best practice, it is recommended that you do not assign a drive letter to your system drive.
Example : Using command bdehdcfg -target default -newdriveletter K: illustrates that default drive is being assigned the drive letter K.-size <SizeinMB> : Specifies the size of the system partition when a new system drive is being created. Default is
300 MB at minimum size is
100 MB.
Example : Use command bdehdcfg -target default -size 500 to allocate 500 MB to the default system drive.-quite : Informs the
BitLocker Drive Preparation Tool that all actions and errors are not to be displayed in the command-line interface.
Example : bdehdcfg -target default -quiet-restart : Use this to restart
BitLocker Drive Preparation Tool after once a operation is completed.
Example : BdeHdCfg.exe -target d: merge -quiet -restartIn this way, you can use BitLocker Drive Preparation command line tool. Interested readers may visit
TechNet and
KB933246 to find out further possibilities.