Short description of Folder Castle 4.1: Folder Castle protects your personal data from snoopers and thieves. You can either lock away files and folders, or put them into Secure Storage with on-the-fly AES-256 encryption. Protected data cannot be seen or accessed in Windows Explorer even in Windows Safe Mode. Folder Castle can even hide its own presence. It's also possible to protect data on the removable drives and take it with you anywhere without the fear of data loss or theft.