It's interesting stuff. If you go to PGP.com they explain it very well. Basically it encrypts the entire hard disk so that when it boots up, it first goes to a screen for a password/passphrase. It uses 256 AES (most banks use 128 at the moment) and takes (in theory) 1000's of years for someone with today's best program to brute force open it. It also depends on the length and difficulty of the password and all of that. But this is true with any AES encryption because it's a standard. Here's a small article from Mark Minasi & for people familiar wth networking & security, they know the books he writes: http://searchwindowssecurity.techtarget.com/generic/0,295582,sid45_gci1260747,00.html "BitLocker Full Volume Encryption, does indeed use AES in 128-bit and 256-bit encryption." You are suppose to also be able to encrypt your page file although this article advises not to. I even found a way to encrypt my backups with a program & then burn it to dvd. If I need to watch it, decrypyt & burn it to a DVD+RW and watch it. After I'm done, overwrite it.