Hi! Thanks man for answer me all time!
I solve this problem using C#, because I don't have atmega8, and I think it's better to don't have atmega8 on this project. And another thing is I don't know if Keyboard.h works in all games, because when I use C, I need to do a DirectInput, and not a normal input to works in all games. If the Keyboard.h was elaborated with a normal input, then it will not work in game.
Another thing to ask is(I don't know if I need to create another topic or no): How to start an application, for example .exe when I plug in the arduino?