BUT I have the impression that not one of them resembles the images I see flashing up when I start a new game - so it seems I can't watch the intro. :/
There's two intro cinematics for Darkstone ... a short "title intro" and the other a somewhat longer one. Don't remember if they're both in the movie folder, but maybe that's the source of your confusion? They're on YouTube, btw. :)
First Second As to them not playing...I think you can get them to work in Wine these days, but not sure about Win7. When I was able to get the original disc game to run on Win7, I remember the Darkstone Won't Shine song audio wouldn't play (for me) when standing in center of town, but I think the movies worked.
Edit: Apparently the videos use the "Indeo 5" codec, so if you don't have that on your computer, maybe that's a reason?