Abstract: A window mounting system including: a track member having a base for attachment to a window frame; a side wall extending transversely to the base; and a cover extending from the side wall parallel to the base having a curved shape facing the base, the distal end of the cover being spaced from the base to form an opening; and a slide member including a runner having a curved shape for nesting in the track member and slidingly engaging therewith, the width of the runner being greater than the width of the opening between the cover and base of the track member to allow for snap-insertion; a runner extension; and glazing support means fixed to the runner extension.