No lighting being applied

Hello all! I am currently trying to just test some lighting in a project and am running into a very annoying issue: When I try and render the scene (with any type of lamp or world lighting) all I receive is the following render.

I have opened another file to confirm that the settings I am using are correct and the other file functions perfectly fine… I am very confused as to what I need to do just to get some simple lighting in the scene working and I literally cannot think as I have spent the last 2 hours just trying to get this working; any help would be much appreciated!

Please disregard the above post, I determined the lighting for the scene could work with the current settings but have the materials applied to objects be set to shadeless; sort of creates a flat image but it works for what I need. Any insight on how to get the lighting back to standard would be lovely though!

Did you say that the materials are set to shadeless? If so then that is your problem, shadeless just makes it so lighting does not affect it.