Exploring BitLocker Drive Encryption
BitLocker Drive Encryption uses encryption to protect data on entire volumes. In contrast, EFS encrypts individual files. There are two flavors of BitLocker: BitLocker and BitLocker To Go.
BitLocker encrypts volumes or partitions. If a single hard drive is configured as two partitions (such as C: and D:), BitLocker can encrypt D: without encrypting C:.
You can use BitLocker to encrypt entire volumes within Windows 7, Windows Vista, Windows Server 2008, and Windows Server 2008 R2. You can also use BitLocker To Go to encrypt removable USB flash drives on Windows 7 and Windows Server 2008 R2 systems.
BitLocker is available only on the Ultimate and Enterprise versions of Windows 7 and Windows Vista.