ALH Offers Silver Line Windows & Doors Silver Line® Windows & Doors are the Nation's leading vinyl window and door manufacturer. Since they first opened their doors in 1947, they've been committed to producing exceptional windows - windows that enhance the home and improve the life of the homeowner. Windows that provide builders, architects and ultimately homeowners with energy-efficient, low-maintenance solutions that add beauty and charm to any home. They believe that form follows function, so before they make their windows beautiful, they make them strong and durable. Every Silver Line® window and door is rigorously tested to provide satisfaction. Satisfaction that results from their comprehensive "Peace of Mind" Limited Lifetime Warranty.