Laptop data encryption is useful in the following cases:

• Prevent users from accessing files when your laptop gets stolen
• Special security policies for sensitive files of large enterprises or governments
• In case you have illegal documents and don't want your government to ever retreive the contents of them (I am not supporting this)

I have compiled a list of available software you can use to encrypt any laptop at my homepage here: Best Encryption Software Top 5

There are some important things you need to know when encrypting data. You should never forget the password! If you do forget it, there is absolutely no way to access the files anymore. If this wouldn't be the case the encryption software would not be secure. So you better remind this never forget your password.

The other thing is a laptop is actually the same as a desktop PC when it comes to encryption. This means you can use existing free and commercial encryption software described at the home page of this website here: Best Encryption Software

What is encryption exactly?

Encryption is a way to encode files with a special key, to access the files you need to decrypt using the encryption key. There are several algorithms which are used to encrypt files: AES, RSA, Serpent, Twofish and many more.

This is probably the most simple explanation I could give as a I'm not a specialist in encryption. For a more detailed explanation take a look here: http://en.wikipedia.org/wiki/Encryption

1. Master Voyager

Easy to use interface. It uses AES 256 bit encryption method. Master Voyager makes it possible to:

• Password protect any DVD or CD
• No need to worry about where to store your DVDs
• Even if you USB / CD / DVD gets stolen, nobody will be able to see your senstive files
• Never go through the long proces of decrypting DVDs anymore! Just fill in your password and Master Voyager will do the rest.

Download Master Voyager

2. TrueCrypt

Truecrypt came at number 2, because it was not as easy to use as Master Voyager. If you are already quite familiar with Truecrypt. Truecrypt maybe able to fullfill your needs. This is what you need to do when using truecrypt: Create a file hosted volume and burn it unto CD, like you burn a normal file. (Credit goes to Stormfront)

3. Ripguard

Ripgaurd is used for publishers, who want to protect their DVD against piracy. I put this one in the list at last, because not so many people will use this. Ripguard will encrypt DVD's in a special way so they can not be copied.
Official Site Ripguard

If you find any dvd encryption software that should be listed here, please place a comment.

If you got some sensitive files you don't want anybody to see, Truecrypt is your friend! Truecrypt makes it possible to encrypt an entire partition or any storage device.

The only downside is that you can't easily encrypt a single existing folder. If you are looking to encrypt a single folder you should take a look at Folder Lock, which uses an easy interface to encrypt your folders.

You can download Truecrypt here: Dowload

	TrueCrypt - File Encryption
Price	Free, Open Source (Although not approved by all as open source: wikipedia)
Platforms	Cross platform. Available on Windows, Mac, Linux.
Security	I would say the security is well enough for the avarage user. Although for users, for whom security is a really important point, I suggest to look here which explains the attacks possible : Security Concerns
Performance	Good. If you got a normal desktop these days, it will run and you won't notice a thing. Some older PC's may notice a small performance hit.
Algorithms	Truecrypt gives you the choice between: AES, Serpent and Twofish. They even give you the choise to combine them.

I will be updating this post, while trying other software. This has been written doing some simple desk research. A more detailed review will come later.