Fort - Cryptography Extension for Windows v2.0

Shareware
Vista / Win7 / Win8 / WinXP

Fort is a cryptography extension for Windows that integrates with explorer so you can easily encrypt and decrypt files.

Key Features:

Windows Explorer integration
Open source, study the code
Uses AES with 256bit keys
Detects data tampering
Very lightweight, does not slow down your machine
Easy to use and easy to install.
Optional file backup before encryption
Encrypt and decrypt directories as well as individual files
Protect against keyloggers, supports on screen keyboard
Encrypt files in Onedrive, Dropbox and similar services
Supports Windows Vista, 7, 8 and 10. Both 32bit and 64bit versions
No backdoors, no malware
Well designed FortMachine.dll cryptography library available for developers
It's possible to buy a licence exception to use FortMachine.dll in closed source products
Fort has it's own file associations, double click an encrypted file to decrypt it.