Help protect your files using BitLocker Drive Encryption

Turning on BitLocker Drive Encryption (BitLocker) can help protect all files stored on the drive Windows is installed on, and on data drives on the same computer.

Unlike Encrypting File System (EFS), which enables you to encrypt individual files, BitLocker encrypts the entire drive, including the Windows system files necessary for startup and logon. You can log on and work with your files normally, but BitLocker can help block hackers from accessing the system files they rely on to discover your password, or access your hard disk by removing it from your computer and installing it in a different computer. BitLocker can only help protect files that are stored on the drive that Windows is installed on, and on data drives on the same computer. If you want to encrypt a data drive, you'll also need to encrypt the drive Windows is installed on since the key for the data drive is stored on the Windows drive. If you store files and folders on other drives, such as USB flash drives or external hard drives, you can help protect them with EFS. You can also encrypt files and folders on BitLocker-encrypted drives for further security on a shared computer. For more information, see What is Encrypting File System (EFS)?

When you add new files to the drive with BitLocker, BitLocker encrypts them automatically. Files remain encrypted only while they are stored in an encrypted drive. Files copied to an unencrypted drive or another computer are decrypted. If you share files with other users, such as through a network, these files are encrypted while stored on the encrypted drive, but they can be accessed normally by authorized users.

During computer startup, if BitLocker detects a system condition that could represent a security risk (for example, disk errors, a change to the BIOS, or changes to any startup files), it will lock the drive and require a special BitLocker recovery password to unlock it. Make sure that you create this recovery password when you turn on BitLocker for the first time; otherwise, you could permanently lose access to your files.

BitLocker typically uses the Trusted Platform Module (TPM) chip in your computer to store the keys that are used to unlock the encrypted hard disk. When you log on to your computer, BitLocker asks the TPM for the keys to the hard disk and unlocks it. Because the TPM provides BitLocker with the keys immediately after you've logged on to your computer, the security of your computer relies on the strength of your logon password. If you have a strong password that prevents unauthorized users from logging on, the BitLocker-protected hard disk will remain locked.

For information about creating strong passwords, see Tips for creating a strong password. To learn how to increase your computer's security by requiring a password to clear away the screen saver, see Use your Windows password for your screen saver password. If your computer is managed by Group Policy, you might be able to use a USB device or startup key which can provide additional logon security. Ask your administrator about using BitLocker with a USB device or startup key.

For detailed instructions on using BitLocker, go to the Windows BitLocker Drive Encryption Step-by-Step Guide on the Microsoft TechNet website.

You can turn off BitLocker at any time, either temporarily by disabling it, or permanently by decrypting the drive.

To turn on BitLocker

1. Open Bitlocker Drive Encryption by clicking the Start button , clicking Control Panel, clicking Security, and then clicking Bitlocker Drive Encryption.‌  If you are prompted for an administrator password or confirmation, type the password or provide confirmation.

2. Click Turn On BitLocker. This opens the BitLocker setup wizard. Follow the instructions in the wizard.

Note

You might have to address one or more BitLocker hardware requirements before you can turn on BitLocker. For more information, see Hardware requirements for BitLocker Drive Encryption.