It is best to install not simple double -glazed windows, but windows with glasses protected from broken — these are triplex and hardened glass, like in the windshield of cars — you can smash them only when colliding at very high speed, with very high force. Triplex is especially good — it opposes not only shock, but also glass cutter. In addition, it is almost impossible to break it — only cracks will go, and the glued layers of glass and films will not crumble.