What is the scientific concept behind windows ?

Their molecules, silicon dioxide, are transparent to visible light. It is probably related to the electrons not absorbing electromagnetic radiation or in other words they lack some range of possible electron promotions to higher energy levels where they can absorb a photon of visible light and gain energy. They don't absorb visible light because their electrons don't absorb the energy in that range of energy.

The scientific concept of Microsoft Windows is that the average user is too stupid to actually understand how a computer works and are too lazy to learn even the simplest of things so everything needs to be as dumbed down as possible so that even a brain dead potato could operate it

Depends upon which window you are in front of