Abstract: A window frame system includes four basic profiles for new building construction and for various other projects including renovation, bow and bay constructions. One profile includes an outer profile for engagement with the wall of a new building in which the distance between the inside wall of the profile and a nailing fin is at least 6.5 inches. The height of the profile is then reduced to accomodate this larger width. A cross mullion is provided and a sash frame profile is also provided. The inner wall of the outer frame and the side walls of the mullion are arranged for cooperation either with a picture window unit or with the sash frame. The fourth profile comprises a renovation/bow profile which can be inserted into an existing window frame or can be snapped together alongside similar profiles to form a bow or bay construction.