EG File Encryption is an easy-to-use freeware file/folder encryption utility.
You will be able to encrypt all your private data files and folders preventing anyone without the password from accessing them. Any file or folder that has been encrypted can still be renamed or deleted, but access will be denied. You do have the option also to encrypt the file if you choose.
EG File Encryption provides a relatively secure option for encrypting files and folders without a lot of unnecessary or overly complex features. But perhaps it should be considered more of a local encryption utility rather than a super secure keep the NSA from looking at your files/folders type utility. As with any encryption app, you should make sure to remember your password, so you aren't the one locked out, but EG File Encryption does allow you to set a hint just in case.