One thing I found is that he's got three audio reproducing devices: Realtek, Nvidia audio and XSplit. Apparently he's not using the speakers of his monitor through HDMI, so the Nvidia audio drivers should be removed and the device disabled.
I have a vague memory about the gamma adjusting issue being discussed not too long ago, but can't remember the solution. It might be this: When starting the game, on the splash screen clipboard go to Video Settings and see if the Max Texture Size box is empty. There should be a value which can be chosen from the drop down menu. In his case 4096 should be the default.
