1.installed successfully.
4. I meant just graphic settings
resolution and some other stuff. yes I know why it happened. so that proves what I thought problem isn't with settings.
yes you can (but you need to restart). and setting it manually didn't help either.
here is another thing I am thinking about: maybe, somehow game sends sound signal through HDMI cable, which is connected through my monitor ( I have GTX660 and it is an audio device as well). well it isn't even selected as audio device and I have never actually used it for audio but... who knows. But that isn't much possible.