I have downloaded and installed the window generator add-on and indeed when I go shift>A add window it shows up the default. The problem comes from when I go to change the parameters the window just vanishes. Probably a stupid noob thing but my project is at a standstill until I figure it out. Any help appreciated.
Well after more research it turns out that the windows generator in 2.79 is somehow over ridden by archimesh which comes with 2.79.....all you have to do is check the box in add-ins and voila