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BitLocker Drive Encryption Step-by-Step Guide

  • Articolo

Applies To: Windows Server 2008, Windows Vista

This step-by-step guide provides the instructions that you need to set up Windows® BitLocker™ Drive Encryption in a test lab environment. We recommend that you do not use this guide in a production environment. Step-by-step guides are not necessarily meant to be used to deploy Windows Server® 2008 operating system features without additional documentation (as listed in the Additional Resources section) and should be used with discretion as a stand-alone document.

What is BitLocker Drive Encryption?

BitLocker is a data protection feature available in the Windows Vista® Enterprise and Windows Vista® Ultimate operating systems for client computers and in the Windows Server 2008 operating system. BitLocker provides enhanced protection against data theft or exposure on computers that are lost or stolen, and more secure data deletion when BitLocker-protected computers are decommissioned.

Data on a lost or stolen computer is vulnerable to unauthorized access, either by running a software attack tool against it or by transferring the computer’s hard disk to a different computer. BitLocker helps mitigate unauthorized data access on lost or stolen computers by combining two major data-protection procedures:

  • Encrypting the entire Windows operating system volume and data volumes on the hard disk. BitLocker encrypts all user files and system files in the operating system volume, including the swap and hibernation files, and can also encrypt data volumes.

  • Checking the integrity of early boot components and boot configuration data. On computers that have a Trusted Platform Module (TPM) version 1.2, BitLocker leverages the enhanced security capabilities of the TPM to help ensure that your data is accessible only if the computer’s boot components appear unaltered and the encrypted disk is located in the original computer.

BitLocker is tightly integrated into Windows Vista and Windows Server 2008 and provides enterprises with enhanced data protection that is easy to manage and configure. For example, BitLocker can use an existing Active Directory Domain Services (AD DS) infrastructure to remotely store BitLocker recovery keys. BitLocker also provides a recovery console that enables data retrieval for non-domain-joined computers or computers that are unable to connect to the domain (for example, computers in the field).

Who should use BitLocker Drive Encryption?

This guide is intended for the following audiences:

  • IT planners and analysts who are evaluating the product

  • Security architects

In This Guide

The purpose of this guide is to help administrators become familiar with the BitLocker Drive Encryption feature of Windows Server 2008. The sections below provide basic information and procedures that administrators need to start configuring and deploying BitLocker within their networks.

Scenario 1 provides instructions for creating the two partitions required for BitLocker Drive Encryption. Scenario 2 describes how to install BitLocker on a server. Scenario 3 explains how to encrypt a hard disk by using BitLocker and a TPM. Scenario 4 describes using BitLocker to encrypt data volumes on a server. Scenario 5 describes using BitLocker on a computer without a TPM. Scenario 6 describes how to access encrypted data after lockdown, and how to test BitLocker by generating a lockdown. Scenario 7 guides you through turning off BitLocker.

Note

The scenarios discussed in this guide pertain to using BitLocker Drive Encryption with operating system volumes. When the operating system volume is encrypted, BitLocker can also be used to encrypt fixed data volumes.

  • Requirements for BitLocker Drive Encryption

  • Scenario 1: Partitioning a Hard Disk for BitLocker Drive Encryption

  • Scenario 2: Installing BitLocker Drive Encryption

  • Scenario 3: Turning on basic BitLocker Drive Encryption

  • Scenario 4: Turning on BitLocker Drive Encryption for Server Data Volumes

  • Scenario 5: Turning on BitLocker Drive Encryption on a computer without a compatible TPM

  • Scenario 6: Recovering Data Protected by BitLocker Drive Encryption

  • Scenario 7: Turning off BitLocker Drive Encryption

  • Additional Resources

Requirements for BitLocker Drive Encryption

These steps are for testing only. This guide should not be the only resource you use to deploy Windows Server 2008 or Windows Vista features.

Hardware and software requirements

  • A computer that meets the minimum requirements for Windows Server 2008.

  • A TPM version 1.2, turned on. (Scenarios 3 and 4).

  • A Trusted Computing Group (TCG)-compliant BIOS (Scenarios 3 and 4).

  • Two NTFS disk partitions, one for the system volume and one for the operating system volume. The system volume partition must be at least 1.5 gigabytes (GB) and set as the active partition (Scenario 1).

  • A BIOS setting to start up first from the hard disk drive, not the USB or CD drives.

Note

For any test that includes the USB flash drive, your BIOS must support reading USB flash drives at startup.

  • We strongly recommend that you do not run a kernel debugger while BitLocker is enabled, because encryption keys and other sensitive data can be accessed with the debugger. However, you can enable kernel debugging before you enable BitLocker. If you enable kernel debugging after you have enabled BitLocker, the system will automatically start the recovery process every time you restart the computer. If you enable boot debugging (kernel debugging with the "-bootdebug" option), the system will automatically start the recovery process every time you restart the computer.

Scenario 1: Partitioning a Hard Disk for BitLocker Drive Encryption

For BitLocker to work, you must have at least two partitions on your hard disk. The first partition is the system volume; the system volume is labeled S in this document. This volume contains the boot information in an unencrypted space. The second partition is the operating system volume; the operating system volume is labeled C in this document. This volume is encrypted and contains the operating system and user data.

The partitions must be created before installing Windows Server 2008.

Note

In some situations, a volume can involve multiple partitions. This document discusses only simple volumes, where a volume and a partition are functionally equivalent. BitLocker works with volumes, a logical structure; but many disk tools are concerned with physical disk partitions.

Scenario 1 describes how to create the two partitions required for BitLocker. This procedure assumes that you have backed up any data on the disk.

If you have an unused disk with a single partition, follow the steps in Partition a disk with no operating system for BitLocker.

  • If you have an unused disk with a single partition, follow the steps in Partition a disk with no operating system for BitLocker.

Note

Make sure that you have backed up any data and that you have your product key for Windows Vista.

Note

If you have already installed Windows Vista, you might be able to use the BitLocker Drive Preparation Tool to configure the volumes required for BitLocker without reinstalling the operating system. For more information, see https://go.microsoft.com/fwlink/?LinkID=83261.

Partition a disk with no operating system for BitLocker

In this procedure you start the computer from the product DVD and then enter a series of commands to do the following:

  • Create a new 1.5 GB primary partition.

  • Set this partition as active.

  • Create a second primary partition using the rest of the space on the disk.

  • Format both new partitions so they can be used as Windows volumes.

  • Install Windows Server 2008 on the larger volume (drive C).

Note

The active partition described above is needed for BitLocker to work properly.

Your drive letters might not correspond to those in this example. In this example, the operating system volume is labeled C, and the system volume is labeled S (for system volume). In this example, we also assume that the system has only one physical hard disk drive.

To partition a disk with no operation system for BitLocker

  1. Start the computer from the Windows Server 2008 product DVD.

  2. In the initial Install Windows screen, choose your Installation language, Time and currency format, and Keyboard layout, and then click Next.

  3. In the next Install Windows screen, click Repair your computer, located in the lower left of the screen.

  4. In the System Recovery Options dialog box, make sure no operating system is selected. To do this, click in the empty area of the Operating System list, below any listed entries. Then click Next.

  5. In the next System Recovery Options dialog box, click Command Prompt.

  6. Use Diskpart to create the partition for the operating system volume. At the command prompt, type diskpart, and then press ENTER.

  7. Type list disk to obtain summary information about each disk partition on the computer. For this procedure, disk 0 is the disk partition used for the system volume. Your computer may have different numbers assigned to the disk partitions, so verify that the partition you select in the next step is one that does not contain any valuable data that you need to retain.

  8. Type select disk 0.

  9. Type clean to erase the existing partition table.

  10. Type create partition primary size=1500 to set the partition you are creating as a primary partition.

  11. Type assign letter=S to give this partition the S designator.

  12. Type active to set the new partition as the active partition.

  13. Type create partition primaryto create another primary partition. You will install Windows on this larger partition.

  14. Type assign letter=C to give this partition the C designator.

  15. Type list volume to see a display of all the volumes on this disk. You will see a listing of each volume, volume numbers, letters, labels, file systems, types, sizes, status, and information. Check that you have one DVD installation volume and two disk volumes and that you know the label used for each volume.

  16. Type exit to leave the Diskpart application.

  17. Type format c: /y /q /fs:NTFS to properly format the C volume.

  18. Type format s: /y /q /fs:NTFS to properly format the S volume.

  19. Type exit to leave the command prompt.

  20. In the System Recovery Options window, use the close window icon in the upper right (or press ALT+F4) to close the window to return to the main installation screen. (Do not click Shut Down or Restart.)

  21. Click Install now and proceed with the Windows Server 2008 installation process. Install Windows Server 2008 on the larger volume C (the operating system volume).

Scenario 2: Installing BitLocker Drive Encryption

Scenario 2 outlines how to install BitLocker Drive Encryption on a server. On a server installation, you must install the BitLocker feature.

Before you start

  • You must be logged on as an administrator.

Note

Installing BitLocker will require restarting the server.

To install BitLocker during initial configuration

  1. When you install Windows Server 2008, the Initial Configuration Tasks window appears.

  2. Choose Add features, and then install BitLocker Drive Encryption.

  3. Restart your server.

You can also install BitLocker by using Server Manager.

To install BitLocker after installation with the Windows user interface

  1. Click Start, click Server Manager, click Add Features, and then click BitLocker Drive Encryption.

  2. Restart your server.

You can also install BitLocker at a command prompt.

To install BitLocker after installation by using Command Prompt

  1. Open a command prompt window as an administrator. To do this, click the Start button, click All Programs, and then click Accessories.

  2. Right-click Command Prompt, and then click Run as administrator.

  3. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  4. At the command prompt, type the following:

    ServerManagerCmd -install BitLocker -restart

    This installs BitLocker if you have not already installed it.

  5. Restart your server.

Scenario 3: Turning on basic BitLocker Drive Encryption

Scenario 3 outlines the procedures for turning on BitLocker Drive Encryption protection on a system with a TPM. After the volume is encrypted, the user logs onto the computer normally.

Before you start

  • You must be logged on as an administrator.

  • BitLocker must be installed on this server.

  • You can configure a printer to print recovery passwords.

To turn on BitLocker Drive Encryption

  1. Click Start, click Control Panel, click Security, and then click BitLocker Drive Encryption.

  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  3. On the BitLocker Drive Encryption page, click Turn On BitLocker on the operating system volume. A message appears, warning you that BitLocker encryption might have a performance impact on your server.

    If your TPM is not initialized, you will see the Initialize TPM Security Hardware wizard. Follow the directions to initialize the TPM and restart or shut down your computer.

  4. On the Save the recovery password page, you will see the following options:

    • Save the password on a USB drive. Saves the password to a USB flash drive.

    • Save the password in a folder. Saves the password to a folder on a network drive or other location.

    • Print the password. Prints the password.

    Use one or more of these options to preserve the recovery password. For each option, select the option and follow the wizard steps to set the location for saving or printing the recovery password.

    When you have finished saving the recovery password, click Next.

Important

The recovery password will be required in the event the encrypted disk must be moved to another computer, or changes are made to the system startup information. This password is so important that we recommend that you make additional copies of the password and store it in safe places to assure you access to your data. You will need your recovery password to unlock the encrypted data on the volume if BitLocker enters a locked state (see Scenario 5: Turning on BitLocker Drive Encryption on a computer without a compatible TPM). This recovery password is unique to this particular BitLocker encryption. You cannot use it to recover encrypted data from any other BitLocker encryption session.

Important

Store recovery passwords apart from the computer for maximum security.

  1. On the Encrypt the selected disk volume page, confirm that the Run BitLocker System Check check box is selected, and then click Continue.

    Confirm that you want to restart the computer by clicking Restart Now. The computer restarts and BitLocker verifies whether the computer is BitLocker-compatible and ready for encryption. If it is not, you will see an error message alerting you to the problem.

  2. If it is ready for encryption, the Encryption in Progress status bar is displayed. You can monitor the ongoing completion status of the disk volume encryption by dragging your mouse cursor over the BitLocker Drive Encryption icon in the notification area at the bottom of your screen.

    By completing this procedure, you have encrypted the operating system volume and created a recovery password unique to this volume. The next time you log on, you will see no change. If the TPM ever changes or cannot be accessed, if there are changes to key system files, or if someone tries to start the computer from a product CD or DVD to circumvent the operating system, the computer will switch to recovery mode until the recovery password is supplied.

Scenario 4: Turning on BitLocker Drive Encryption for Server Data Volumes

For servers stored in an environment that is shared or not secure, such as a branch office location, BitLocker can ensure the same level of data protection as it offers client computers by encrypting data volumes and the operating system volume.

The operating system mounts a BitLocker-protected data volume as normal.

The keys for protecting a data volume are independent of the keys protecting the operating system volume. To allow the system to automatically mount these volumes, the key chain protecting the data volume is also stored encrypted on the currently-booted volume. If the operating system enters recovery mode, the data volumes are not unlocked until the operating system is out of recovery mode.

Recovery of a data volume is similar to recovery for an operating system volume. If the data volume becomes corrupt, is moved to a new platform, or the operating system volume cannot retrieve the key for the data volume to automatically unlock it, then the user inserts the media containing a copy of the data volume recovery key.

Important

Your drive letters might not correspond to those in this example. In this example, the operating system volume is labeled C, and the system volume is labeled S (for system volume). In this example, we also assume that the system has only one physical hard disk drive.

Before you start

  • You must be logged on as an administrator.

  • BitLocker must be installed on this server.

  • You must have a USB flash drive to save the recovery password for the data volume(s).

To turn on BitLocker Drive Encryption for server data volumes

  1. Open a command prompt window as an administrator. To do this, click the Start button, click All Programs, and then click Accessories.

  2. Right-click Command Prompt, and then click Run as administrator.

  3. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  4. At the command prompt, type the following:

    start /w pkgmgr /iu:BitLocker

    This installs BitLocker if you have not already installed it.

  5. Restart your server. You have now installed BitLocker, but it is not yet enabled.

  6. From an elevated command prompt, type the following:

    manage-bde –on <volume>: -rp –rk U:\

  7. This command encrypts the named volume, generates a recovery password, and stores a recovery key under U:\ (the USB drive, for example). Record the recovery password and the recovery key filename displayed on the console. The data volume will have to be unlocked after each restart by using either the recovery password or the recovery key as follows:

    • manage-bde –unlock <volume>: -rp <recovery password>

    • manage-bde –unlock <volume>: -rk U:\<recovery-key-file name>

  8. To enable automatic unlocking of data volume, type the following:

    manage-bde –autounlock –enable <volume>:

  9. This command generates a recovery key and stores it on the operating system volume. The operating system volume must be fully encrypted before this command is issued. Once automatic unlocking is enabled, the data volume is automatically unlocked on each restart.

Scenario 5: Turning on BitLocker Drive Encryption on a computer without a compatible TPM

Use the following procedure to change your computer's Group Policy settings so that you can turn on BitLocker Drive Encryption without a TPM. Instead of a TPM, you will use a startup key to authenticate yourself. The startup key is located on a USB flash drive inserted into the computer before the computer is turned on. For this scenario, you must have a BIOS that will read USB flash drives in the pre-operating system environment (at startup). Your BIOS can be checked by the System Check in the final step of the BitLocker wizard.

Before you start

  • You must be logged on as an administrator.

  • BitLocker must be installed on this server.

  • You must have a USB flash drive to save the recovery password.

  • We recommended that you use a second USB flash drive to store the startup key separate from the recovery password.

To turn on BitLocker Drive Encryption on a computer without a compatible TPM

  1. Click Start, type gpedit.mscin the Start Search box, and then press ENTER**.**

  2. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  3. In the Local Group Policy Editor console tree, click Local Computer Policy, click Administrative Templates, click Windows Components, and then click BitLocker Drive Encryption.

  4. Double-click the setting Control Panel Setup: Enable Advanced Startup Options.

  5. Select the Enabled option, select the Allow BitLocker without a compatible TPM check box, and then click OK.

    You have changed the policy setting so that you can use a startup key instead of a TPM.

  6. Close the Local Group Policy Editor.

  7. To force Group Policy to apply immediately, you can click Start, type gpupdate.exe /forcein the Start Search box, and then press ENTER.

  8. Click Start, click Control Panel, click Security, and then click BitLocker Drive Encryption.

  9. If the User Account Control dialog box appears, confirm that the action it displays is what you want, and then click Continue.

  10. On the BitLocker Drive Encryption page, click Turn On BitLocker. This will only appear with the operating system volume.

  11. On the Set BitLocker Startup Preferences page, select the Require Startup USB Key at every startup option. This is the only option available for non-TPM configurations. This key must be inserted each time before you start the computer.

  12. Insert your USB flash drive in the computer, if it is not already there.

  13. On the Save your Startup Key page, choose the location of your USB flash drive, and then click Save.

  14. On the Save the recovery password page, you will see the following options:

    • Save the password on a USB drive. Saves the password to a USB flash drive.

    • Save the password in a folder. Saves the password to a folder on a network drive or other location.

    • Print the password. Prints the password.

    Use one or more of these options to preserve the recovery password. For each option, select the option and follow the wizard steps to set the location for saving or printing the recovery password. You should not store the recovery password and the startup key on the same media.

    When you have finished saving the recovery password, click Next.

Important

The recovery password will be required in the event the encrypted disk must be moved to another computer, or changes are made to the system startup information. This password is so important that we recommend that you make additional copies of the password and store it in safe places to assure you access to your data. You will need your recovery password to unlock the encrypted data on the volume if BitLocker enters a locked state (see Scenario 5: Turning on BitLocker Drive Encryption on a computer without a compatible TPM). This recovery password is unique to this particular BitLocker encryption. You cannot use it to recover encrypted data from any other BitLocker encryption session.

Important

Store recovery passwords apart from the computer for maximum security.

  1. On the Encrypt the selected disk volume page, confirm that the Run BitLocker System Check check box is selected, and then click Continue.

    Confirm that you want to restart the computer by clicking Restart Now. The computer restarts and BitLocker verifies whether the computer is BitLocker-compatible and ready for encryption. If it is not, you will see an error message alerting you to the problem before encryption starts.

  2. If it is ready for encryption, the Encryption in Progress status bar is displayed. You can monitor the ongoing completion status of the disk volume encryption by dragging your mouse cursor over the BitLocker Drive Encryption icon in the notification area at the bottom of your screen or clicking on the Encryption icon.

    By completing this procedure, you have encrypted the operating system volume and created a recovery password unique to that volume. The next time you turn your computer on, the USB flash drive with the startup key must be plugged into a USB port on the computer. If it is not, you will not be able to access data on your encrypted volume.

    If you do not have the USB flash drive containing your startup key, then to access the data, you will need to use recovery mode and supply the recovery password.

Scenario 6: Recovering Data Protected by BitLocker Drive Encryption

Scenario 5 describes the process for recovering your data after BitLocker has entered recovery mode. BitLocker locks the computer when a disk encryption key is not available. The following is a list of likely causes:

  • An error related to TPM occurs.

  • One of the early boot files is modified.

  • The TPM is inadvertently turned off and the computer is turned off.

  • The TPM is inadvertently cleared and the computer is turned off.

When a computer is locked, the startup process is interrupted very early, before the operating system starts. You must use the recovery password from a USB flash drive, or use the function keys to enter the recovery password. F1 through F9 represent the digits 1 through 9, and F10 represents 0.

Because recovery happens so early in the startup process, the accessibility features of Windows are not available. If you require accessibility features, consider what you will do in the event of recovery.

This scenario includes two steps:

  • Testing data recovery

  • Recovering data

To test data recovery

  1. Click Start, point to All Programs, click Accessories, and then click Run.

  2. Type tpm.msc in the Open text box, and then click OK. The TPM Management Console is displayed.

  3. Under Actions, click Turn TPM Off.

  4. Provide the TPM owner password, if required.

  5. When the Status panel in the TPM Management on Local Computer task panel reads "Your TPM is off and ownership of the TPM has been taken," close that task panel.

  6. Close all open windows.

  7. If the USB flash drive that contains your recovery password is plugged into the system, use the Safely Remove Hardware icon in the notification area to remove it from the system.

  8. Click the Start button, and then click the Shutdown button to restart your computer. When you restart the computer, you will be prompted for the recovery password, because the startup configuration has changed since you encrypted the volume.

To recover access to data using BitLocker Drive Encryption

  1. Turn on your computer.

  2. If the computer is locked, the BitLocker Drive Encryption Recovery Console will appear.

  3. You will be prompted to insert the USB flash drive that contains the recovery password.

    • If you have the USB flash drive with the recovery password, insert it, and then press ESC. Your computer will restart automatically. You do not need to enter the recovery password manually.

    • If you do not have the USB flash drive with the recovery password, press ENTER. You will be prompted to enter the recovery password.

      If you know the recovery password, type it, and then press ENTER.

      If you do not know the recovery password, press ENTER twice and turn off your computer.

Note

If you saved your recovery password in a file in a folder away from this computer, or on removable media, you can use another computer to open the file that contains the password. To locate the correct file, find Password ID on the recovery console display on the locked computer, and record this number. The file containing the recovery password uses this Password ID as the file name. Open the file and locate the recovery password in the file.

Scenario 7: Turning off BitLocker Drive Encryption

Scenario 6 describes how to turn off BitLocker Drive Encryption and decrypt the volume. The procedure is the same for all BitLocker Drive Encryption configurations on TPM-equipped computers and computers without a compatible TPM. Data volumes can only be decrypted, not disabled.

When you turn off BitLocker, you can choose to either disable BitLocker temporarily, or to decrypt the volume. Disabling BitLocker allows TPM changes and other minor changes to the system. Decrypting the volume means that the volume will be entirely decrypted, and that all the keys are discarded. You must decrypt a computer before upgrading the operating system. Once a volume is decrypted, you must generate new keys by going through the encryption process again, if you want to enable BitLocker.

Before you start

  • You must be logged on as an administrator.

  • The volume must be encrypted.

To turn off BitLocker Drive Encryption

  1. Click Start, click Control Panel, click Security, and then click BitLocker Drive Encryption.

  2. From the BitLocker Drive Encryption page, find the volume on which you want BitLocker Drive Encryption turned off, and click Turn Off BitLocker Drive Encryption.

  3. From the What level of decryption do you want dialog box, click either Disable BitLocker Drive Encryption or Decrypt the volume as needed.

    By completing this procedure, you have either disabled BitLocker or decrypted the operating system volume.

Additional Resources

The following resources provide additional information about BitLocker Drive Encryption:

For more information about the User Account Control feature, see User Account Control (https://go.microsoft.com/fwlink/?LinkId=66018).