Ruby noob error

Background

I’m an absolute novice at all things development/code related.
Masochisticly I’m trying to leanr Ruby on Rails. It took me an evening
to work out that start>run>command launched something entirely different
to start>run>cmd so this problem probably has an equally obvious
solution.

PROBLEM

I am trying to set up a controller. the command

“ruby script/generate controller Site index about help”

seems to work fine. However although in the directory the files seem to
have been created I can’t see them in my RadRails project window.

When I try and take a look at the controller using

“site_controller.rb” or if I try and look at the application controller
using “application.rb”

I get the error:

D:/ruby/rails_space/app/controllers/application.rb:4: uninitialized
constant ActionController

WHAT AM I DOING WRONG?