LAN Messenger - LAN Messenger is a decentralized UDP IM-style chat client which supports usernames...
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
Softros LAN messenger - LAN messenger for an internal office chat for home or business users. It does not require a server and is very easy to install and use. It supports personal chats, group chats, message brodcasting, files transfer and remote desktop access.
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.
MyChat - Secure instant messenger for any network
Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.