windowed borderless

I was wondering what windowed mode was so i switched to it and then i moved it around and not thinking i changed it to borderless. now my game is half off of the screen and the settings i can open using esc. but when i go to video change it back i cannot access the done/ submit button to change the settings. now i cant play because half my screen is out of my computer and i cant get the settings high enough up to hit submit. anybody please help.