Unlike older windows made of plate glass, modern day windows (or at least as of the last 20 years) are much safer with respect to shattering. Windows today are made with safety glass. The most common type of safety glass is where the glass is coated in clear acrylic or plastic that will hold the pieces together should the window get struck with an object. The glass in effect shatters and remains trapped between the plastic coatings. In addition, the glass breaks into small round pieces that do no have any sharp edges. So applying tape to this type of window does not decrease the chance of sharp fragments being produced nor will increase the strength of the window.
