From Privacy-care Lab:
FolderDefence Free--new, free and extremely easy software to hide, lock and password protect your private files and folders from other users, programs or malicious application. FolderDefence enables you to password protect all the private or sensitive information on your hard drive(s). You can make your files and folders inaccessible, invisible or protect them from modification and deletion. The protected data is not accessible by any users or applications no matter how they are trying to get in locally or from the net. Intuitive user interface of FolderDefence will suit the needs of everyone --from novice Windows users to computer experts. Main features and benefits: Effectivness of files protection allow you to hide folders out from users, applications and malicious software in Windows XP, Server 2003, Vista, Server 2008 and Windows 7. Only the owner of application's master password will access your hidden folders. 4 protection methods available: Hide, Lock, Hide & Lock, Read Only Volumes of all file systems are supported. The number of protected files/folders is unlimited. No file system structure modifications are made while using FolderDefence. Usage and uninstallation of FolderDefence is protected with single password. True stealth mode you cannot detect the protection module. Support for folders named with national language symbols. Full Windows 7 support And, of course, FolderDefence Free is fully free for home and commercial use.