Weeds,
Thomas's post above runs throught the order-of-installation. Specifically:
1. No, the stationary window goes in first (and it therefore becomes the "outside" of the two windows).
2. Thus, the run channel does not butt againts the "outside" flange of the window opening.
3. And thus, the sliding window go inside the run channel and slides past the outside stationary window on the inside (makes sense, because there would be much more wind noise if the slider was on the outside).
Tim
