If you need to capture a room with a big windows, try to do it when the sun is on the other side of the house. Use flash and if the window is not the only light subject in the photos, you should be just fine. Try to line up the window frame and a horizontal line of the landscape behind the window, but in the same time use angles inside of the room. By capturing the image from the far away corner will allow you not to have a flash reflection on the window. Later on adjust light for the window and room separately.