Our 1950s ranch on slab was added on to some time in the 1990s. A wall of rectangular windows that used to be a perimeter/outer wall, is now an interior wall. Surely it's structural, but are the windows integral to the structure? Can I remove the windows but keep the wood framing, and not risk the integrity? In photo, see 2 column grid of eight windows with blue wall of add-on space in distance. Thanks!
The windows themselves will not be structural, and in your case the wood in the middle between the 2 columns will not be either. I see in the picture the rafters over the windows appear to be the same dimension as the rafters of the rest of the ceiling. those rafters have no additional support under them so it is safe to assume that the rafters over the window section can carry the load of the roof on their own without the center post between the windows. The only exception that would be if the rafters were notched to accept the vertical post. That notch would weaken the rafter and not allow you to remove the wall unless the rafter was repaired or replaced.