Lavasoft Digital Lock
With Lavasoft Digital Lock, you can securely encrypt and password protect files, folders, compressed zip and .exe files. Digital Lock is fast and lightweight, and it supports the heavy-duty 256-Bit Advanced Encryption Standard (AES).
Using Lavasoft Digital Lock is easy enough. Just select files for encryption, right-click, and a Lavasoft cursor menu item will give you the option of encrypting the file or folder. You can also configure the program to shred the original file after encryption.
One nice touch: Lavasoft offers a free decrypt program called Lavasoft Encyption Reader. This is handy if you are sending someone a Lavasoft Digital Lock file and the recipient doesn't have the Digital Lock program.