Nuclex.GameControl and Mouse Positions

I am using the Nuclex.GameControl to make a map editor but for some reason the mouses position is relative to the top left corner of the screen instead of the top left corner of the game window.

Any ideas as to why this might be happening?

EDIT: I realised in the images properties in the solution explorer it doesn't have any of the 'XNA Framework Content Pipeline' options.

Was I supposed to make a windows game of windows form when I started the project?