McMahon Window Washing Chicago land’s Most Respected Name in Window Washing & Gutter Cleaning. McMahon Window Washing Inc, located in Schaumburg, Illinois, is Chicagoland’s industry leader for over 15 years. We are a member in good standing with all consumer reporting agencies. We specialize in residential and commercial window cleaning, gutter cleaning and power washing. McMahon Window Washing services individual homes, town home complexes, condominium boards, and commercial buildings throughout Chicago and all suburban areas. We service over 12,000 homes yearly and are approaching 250,000 satisfied customers.