Please help me its been 1 month ________ Black screen when entering in the game (loading scene)+game

After champion selection i have a black screen. When the loading screen appears and also when im enterring in the game. I still can hear the sound and move my character but i dont have image just a black screen! Please help me . The launcher works i can do whatever i want its just i wanna play. -Window 7 But the weird thing is its doing also on dota 2( ive install it to see if it was my computer or the game problem)

Can you please help me , ive shearch everything on ethernet. I heard sound and i can play but the only thing is i have a black screen all the time starting to the loading screen and it continue in the game. But my menu tho works fine.