We Offer Window Replacement And Installation Services In Massachusetts! Our staff provides heavy duty, fusion welded frame and sash windows throughout Massachusetts. These are products that are 50% more energy efficient than state code standards at around 30% better than the energy Star requirements delivered throughout Massachusetts. Window Master warrants that all products are installed in a proper manner and according to Manufacturers specifications and local building code. If during the normal life of any product, it is determined that the product was not installed correctly, then Window Master will, without delay, remove and re install said product, and replace all damaged parts at no cost to the homeowner.