Window cleaning has been a part of the business from the beginning. When we began, there were no tilt in windows. There were mostly wooden windows with 12 panes, 2 storms and a screen. 
In the 35 years since, we have seen every type of window and window cleaning situation. 
We scrape off anything that is on the glass, and clean them without leaving streaks. The frames, sills and window wells get cleaned as well.