Content Security

Question

Actually i'm developing a web based Content Management system in VS-2012. Here the contents(video files and flash files) Needs to be accessed only through the application. I placed all the files in a folder and could be accessible through my application. Currently there is no security provided for that folder. I want that folder to be either password protected or protected hidden, so that even the administrator user of my client machine wont be able to copy the files.
Also those protected files should accessible through that application.

Please Help