me and my friend

Me and my friend is gonna make a team together but what annoys me now is that before he couldnt play because of a problem but now he can play.but before i could play but now i cant because it says cant find proper screen mode for Gr2D. so i feel so bad. Does anyone know how to fix the problem? cos we are best friends in real life.
oh yea 2 more questions 1. how do i take screen shots. 2. how do i make videos. plz tell me