Long Island's Premier Vinyl Window and Door Manufacturer. Since 1989, Royal Windows and Doors has been manufacturing the highest quality uPVC windows for the replacement and new construction markets. We were among the first few companies nationwide to introduce a very high quality, all welded vinyl window line. For the first time, vinyl windows could compete very favorably in looks, functionality and elegance, with the most recognized national brands of wood windows. Most importantly, our windows could outperform these famous brands in durability, ease of operation, and the elimination of the need for constant maintenance. Royal Windows and Doors provides you with the best warranty program in the industry. As an established local manufacturer we are able to give all our customers superior service and support before and after the sale. We rely heavily on our reputation for quality and service to attract and retain new customers, and therefore take both very seriously.