well.....you could check the box "read-only" but that only works for people with absolutely no idea on how PC's work. I do know that you can make a archive with winrar and protect it with an password, but that only protects the archive...
I do think you should search the answer to this question on different kind of forums, not that biorust is a bad place. I think that this is more of a computer/ technical question, and I don't think many people here are true know-how's on that area of pc's
if you get what I mean...