I have a new computer. (yay)
I start a new character, naming him to something like this: ahgagaar, and starts playing.
Works great IN the boat, but when I go up to meet the guard, who by the way is very enthusiastic over meeting you, the entire screen tursn black.
And this is quite annoyng, since its quite hard to play in total darkness.
Anyone experienced the same problem?

Nope, have you tried installing or reinstalling the display drivers? Try that first.
Are you using a video card as well? If so check the manufacturer website for the latest drivers. You could also play around with some of the options to see if there is something that the computer just doesn't like.