AxCrypt is a free, open source file encryption application for Microsoft Windows 95/98/ME/NT/2K/XP integrated into Windows Explorer. Its current cryptographic primitives are AES-128 and SHA-1.

AxCrypt is a powerful, yet extremely easy to use file encryption program. It integrates directly with Windows Explorer, enabling encryption, decryption, viewing and editing of any file with just a few clicks of the mouse. There is no extra interface to configure or open, other than selecting/entering your password.
The portable version of Axcrypt is called Axcrypt2go, still developped by Axantum Software, as a Free Software.