When you try to enable BitLocker drive encryption on the operating system drive (typically drive C) by using themanage-bde.exe -on command, you may receive the following error message:
ERROR: An error occurred <code 0x80070057>
The parameter is incorrect
This problem occurs if you do not have a separate active system partition on the operating system drive.
To resolve this issue, create a separate active system partition that can be used by BitLocker. The steps in this process vary, depending on the operating system that you are using and on whether you are using themanage-bde command or the BitLocker setup wizard.
Assume that you are upgrading from an earlier version of Windows or that you are installing Windows 7 or Windows Server 2008 R2 on a new computer that has a single partition. When you enable BitLocker from Control Panel or from Windows Explorer in this situation, the BitLocker setup wizard automatically configures the target drive for the separate active system partition. However, in some rare instances, you may have to manually prepare the drive for BitLocker. In this situation, use one of the following methods, as appropriate for your operating system.
Windows Server 2008 or Windows Vista:
Use the BitLocker Drive Preparation tool that is discussed in the following Microsoft Knowledge Base (KB) article to create a separate active system partition that can be used by BitLocker:
Windows 2008 Core or Windows Server 2008 R2 with BitLocker feature installed:
Use the BitLocker Drive Preparation tool to create a separate active system partition that can be used by BitLocker. You can find this tool in the C:\Windows\System32 directory.
Use the following bdehdcg.exe command line to create a system partition for BitLocker:
bdehdcfg -target c: shrink -newdriveletter s: -size 300
Note In this command line, "c" represents the operating system drive, "s" represents the drive letter for the new system partition, and "300" represents the size of the partition in megabytes (MB).
You must restart the computer to complete this operation.
Note The Bdehdcfg.exe utility not available in Windows Server 2008 R2 Core. To use this utility in Windows Server 2008 R2 Core, copy the following three files from the C:\Windows\System32 directory of a computer that is running Windows 2008 R2 Enterprise, Windows 2008 R2 Standard, or Windows 2008 R2 Web Full Edition to the C:\Windows\System32 directory of the Windows 2008 R2 2008 R2 Core-based computer that is generating the error:
For more information about how to enable BitLocker by using a command line, visit the following Microsoft Web site: