I need to have two pieces of software, made in vb where one encrypts the contents of a .txt file, and the other decrypts it, and then picks one word at random and displays it each time a button is pressed, but never displays the same word. Or, if there was a way to hard code it into the program as there is only 5 words that would be better.

Same question that has been asked a hundred times before - what have you got so far? I presume this is for an assignment as I cannot think of any other reason to write this. We don't do your homework for you. Show us what effort you have gone to (other than the effort it took to ask us to do it for you).

There are numerous pieces of sample code on this and other web sites that show how to encrypt/decrypt. All you have to do is google.