Require additional authentication at startup (Windows Server 2008 and Windows Vista)

This policy setting allows you to control whether the BitLocker Drive Encryption setup wizard will be able to set up an additional authentication method that is required each time the computer starts. This policy setting is applied when you turn on BitLocker. Note: This policy is only applicable to computers running Windows Server 2008 or Windows Vista. On a computer with a compatible Trusted Platform Module (TPM) two authentication methods can be used at startup to provide added protection for encrypted data. When the computer starts it can require users to insert a USB flash drive containing a startup key. It can also require users to enter a 4-digit to 20-digit startup personal identification number (PIN). A USB flash drive containing a startup key is needed on computers without a compatible TPM. Without a TPM BitLocker-encrypted data is protected solely by the key material on this USB flash drive. If you enable this policy setting the wizard will display the page to allow the user to configure advanced startup options for BitLocker. You can further configure setting options for computers with and without a TPM. If you disable or do not configure this policy setting the BitLocker setup wizard will display basic steps that allow users to turn on BitLocker on computers with a TPM. In this basic wizard no additional startup key or startup PIN can be configured.