Encrypt Entire Drives with BitLocker in windows vista

Screaming headlines in recent years have made the public aware of stolen laptops and
desktop computers that contained the personal records of thousands of millions of individuals.
These thefts might not have exposed anyone’s personal data if the hard drives in
the stolen computers had been encrypted and protected by strong passwords.
Various third-party solutions have long been available to encrypt sensitive data folders
and entire hard drives. With Vista, Microsoft now enters this market with BitLocker Drive
Encryption.
BitLocker has some advantages over competing encryption products because, integrated
as it is into Windows, it can check the integrity of a computer system before the Windows
user interface is ever loaded. BitLocker can tell when a hard drive has been moved to a
different computer—as would be the case if a drive had been stolen—and can defend
against brute-force attacks.
BitLocker also integrates with Microsoft’s Active Directory domain service scheme. The
remote storage of digital keys that can unlock or restore data if a user forgets a password is
a difficult and labor-intensive chore for IT administratrors. BitLocker handles this by using
Active Directory to escrow the keys securely, while still being able to help an authorized
(but forgetful) user access crucial data that’s stored in a password-protected drive.
BitLocker is available only in Vista Ultimate Edition, which can be purchased separately
or upgraded to from the Home and Business Editions, and Vista Enterprise Edition, which
can be purchased separately or upgraded to from the Business Edition.