About Thompson Creek Thompson Creek Window Company is a privately owned and family-operated manufacturer and installer of energy-efficient home improvement replacement products. Founded in 1980, Thompson Creek Window Company began as a manufacturer of maintenance-free, energy-efficient vinyl windows. Since that time, Thompson Creek Window Company has evolved into one of the leading specialty home improvement contracting companies in the nation. The company's product mix includes replacement windows and doors, vinyl siding and a clog-free gutter system. Thompson Creek Window Company is headquartered in Lanham, Maryland and recently moved into a 117,000-square-foot building in Upper Marlboro to house its new manufacturing and warehousing operations. Thompson Creek employs over 400 people in the Washington D.C. and Baltimore, MD region.