This ain't too different from my room and I have had good results with the speakers in front of the windows. However, they are 4-5 feet in front of the windows, there are adjustable acoustic drapes on the windows and I have a bass trap in each of the front corners. The nice thing about this arrangement is that the listening seat, facing the speakers, will have no wall or reflecting surface directly behind. The elimination of a short rear reflection is advantageous.
Kal
Kal