BitLocker To Go, unlike EFS (encrypting file system), offers a way to encrypt full disk with portable storage devices like hard drives or USB flash drives. The feature requires Windows 8 Pro or Enterprise, so the Surface RT does not have BitLocker and you need to have Surface Pro tablet.
How to use BitLocker To Go to Protect hard/Flash drive on Surface Pro
* Open charms bar from start screen, click/tap Search, and type “BitLocker” in the box. Then select it from the setting result, and go to Control Panel > System and security > BitLocker Drive Encryption.
* Plus the external storage devices to a USB port and clcik “Turn on BitLocker”. BitLocker will scan and lock it. Once the drive is initialized, it asks you to “Choose how you want to unlock this drive” using either a password or a smart card. Check “Use a password to unlock the drive” > type your password in the fields > click Next.
* When it prompts you to back up a recovery key which is helpful if you forget password, select which option you want to use, including a Microsoft account, saved to a file, or printed out.
* Click Next and it asks you how to encrypt the drive. For clean drive, select “Encrypt used disk space only”. If there has already stored data, Select “Encrypt entire drive”.
* Click Next > Start encrypting button. To access encrypted drive on the go, you need to enter the correct password.