TrueCrypt - TrueCrypt is a leading cross-platform that provides encryption tools that allow you to migrate any encrypted data to virtual disks images on your systems.
CipherShed - CipherShed is a program that can be used to create encrypted files or encrypt entire drives...
Dekart Private Disk - Dekart Private Disk is a powerful disk encryption software with distinctive features and functions, combining robust NIST-licensed AES 256-bit encryption with a simple and straightforward interface.
AES Crypt - AES Crypt is an advanced file encryption utility that integrates with the Windows shell or runs from the Linux command prompt to provide a simple, yet powerful, tool for encrypting files using the Advanced Encryption Standard (AES).
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
GPG4Win - GPG4Win is an encryption program for files and emails. The program encrypts emails and files so that they can only be read by those intended to receive them.