No, not a dumb question. Unless i'm mistaken, you are looking for this on DVD?
If you're computer does not have sound, you could still watch the video portion. You won't be able to hear the narration, but at least you could have the visuals.
As I understand it, when this video was first made, it was available on a CD. I'm not 100% sure, but I believe it was CD, not DVD. Since then it has been distributed for free over the Internet, so I do not know if it still can be gotten in hard copy.
Here are some suggestions. You can download this video directly from here -