TrueCrypt has been the standard for file and folder encryption since 2004, and it doesn't hurt that it's open-source freeware, either. The latest update includes the power to do more than protect the mere output of your work: you can now encrypt and hide an entire operating system using the program's wizard.
As the step-by-step guide points out when you start it, one of the reasons you might want to create a hidden OS is in case of extortion. A little paranoia doesn't hurt, either. So, when you create the hidden OS, it also creates signposts … Read more