In highly secure environments where Smart Cards are the preferred method for authentication, Windows 7 is the system that allows you to use Smart Cards without requiring any specific vendor software. In addition, Windows 7 allows you to fine tune the authentication mechanism through the use of policies. Why Smart Cards? Smart Cards are more secure than other means of authentication such as user names and passwords. They store digital certificates where an administrator can immediately revoke the certificate stored on a lost or stolen Smart Card from the system.
To enable BitLocker on your computer you need administrator privileges and your computer has to have the appropriate TPM hardware or the appropriate Group Policy if TPM is not present. A check is performed after you enable BitLocker and an error is displayed in case your computer does not support BitLocker. Go here for more information.
Windows 7 supports different password-based and certificate-based authentication protocols that can be used for both dial-up and VPN connections. Windows 7 first tries to use the most secure authentication protocol that is enabled and then falls back to less secure protocols if they are available.