Thank you for your response.
Though I'm afraid I wasn't too clear, as you seem to have misunderstood me. I know how to make a window go into Fullscreen mode already.
Though when I use a screen resolution that is smaller than the current resolution of the computer, it makes black space/borders around the screen during Fullscreen.
This is most likely because I am using a 4:3 Resolution (800x600) on a 16:10 Monitor (1280x800). Is there a way to instead stretch pixels of the screen the image to fit the monitor.
I'm going to use an image to try to help explain what I want to do.