Some guy

Actually, this is one of the few VN's that try to take incest in a serious manner.

Agreed, even if they took out the hscenes I would still have enjoyed reading this. They explore the subject from all kinds of angles, social, emotional, ethically, etc. Even if a person disapproves of the subject, Yosuga no sora will at least provide perspective, rather then just shutting your eyes and holding your hands over your ears.

I actually wish they had taken a more serious approach with all the VNs i've read, that involve "close relations". Kanon, G-Senjou no Maou, Hoshizora no Memoria, Tsukihime - and I'm sure others (not listing imo para lol, too absurd to be even remotely serious). They all just sort of silently accept it, like it's "o.k." without any doubts or concerns; and it usually works - but the extra layer of depth/dilemma could add interesting character development.

Besides, as someone with no family, it's not something I can relate to (for it or against it) but the idea of two finding love - regardless of who they are, is beautiful - and hurts no outsider.

"vol.1" - Is this a ongoing story broken into parts then? or more of a set of self-contained stories?

I'll start off with the more commen solutions - not sure about win8, but for other OSs a key thing to getting VNs to install and run is to set your locale to Japanese in Regions and settings under control panel.

From there, it should install without issues or bugs - albeit you will still have to guess your way through the install prompts, being a different language regardless.

EDIT: alternately, there is a english localized version floating around out there that doesn't require any fiddling around to run.