Encrypto - Encrypto lets you encrypt files before sending them to friends or coworkers.

Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.

File Lock PEA - Password-encryption of files and directories. File PEA encrypts files and folders with authenticated encryption to protect confidentiality and integrity. The program uses memory-hard key derivation functions to prevent custom hardware attacks.

VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.

Unicode Crypter - Encrypt and Decrypt Unicode!

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.