I have 5 double hung wood windows that need repair (among other things) and hired a contractor who said that he knew how to repair the windows. The windows have rot damage in some areas and the top window sash on almost all of the windows would not stay shut. (All of the top windows would slide down a few inches.) My "contractor" did not properly repair the windows... he screwed the top window sash permanently closed on the inside of the frame... basically, he screwed the window part to the vinyl track part. The obvious problem is that half of the function of the window is now lost. The screw is ugly and obviously does not belong or look professional. My question is this for anyone that knows anything about wood windows... what other problems does this cause or could cause in the future? (I am only beginning to research how wood windows and double hung windows operate.)