Prey starts up in small window on desktop

[Recklessness]

After I beat the demo it had an option to preorder or go to Prey website and I selected one of them and it minimized the screen and now I don't know how to get it to start up in full screen. It just opens up in a small window on my desktop every time i try to play it.

Probably something simple im sure, so any ideas? Thanks in advance. :o

[Recklessness]

Alright nevermind I figured it out, it apparently changed my full screen option in the main menu.