USB Safeguard - Password protection software USB pen drive
Windows BitLocker - This topic provides a high-level overview of BitLocker, including a list of system requirements, practical applications, and deprecated features.
VeraCrypt - VeraCrypt is a free open source disk encryption software for Windows, Mac OSX and Linux.
USB Secure - Password Protect Your USB Drive And All Its Private Contents.
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.
Axcrypt - AxCrypt - Password Protect Files With Strong Encryption. AxCrypt is the leading open source file encryption software for Windows.