Folder Castle allows you to both hide selected folders on your computer so that they require a password to be able to access them and also to set up secure areas for storing information that needs to be properly encrypted if it is to be kept on your computer.
This software would be extremely useful if all the options that it appears to include actually worked properly the way the documentation describes. Unfortunately when I tested the program many of the options just failed to work at all. Now the reason for this is probably due to the fact that I have my computer set up with a whole range of security features installed and something in the security is preventing those options from working. Presumably for those silly enough to work from an account with administrator access and who don't have proper security in place the other options would work. My only query would be why the writers of this software didn't test it properly in the sort of environment that people should have set up for general use on their computer.
The actual hide and unhide functions do actually work to prevent others from seeing certain folders and so this software can be used to hide folders under your personal login that you don't want other people who use the computer to be able to see from their login. Unfortunately the only way of being able to hide and unhide folders is to have the toolbar enabled which makes it really obvious to everyone using the computer that the software is there and that someone has hidden files.
That most of the functionality doesn't work is a shame because if it did the program would be a lot more useful. Of course all those options probably would work if the correct steps were followed in setting them up but the help doesn't include any clues as to what those steps are.