Where are the GUI window coords stored?

I'm sure the answer is staring me in the face but when a client has moveable windows and they are dragged all over hells half acre where does the client store those settings on exit?

Basically the x y values of the position and the extent for moveable/resizeable windows. I think what Im asking for is where is the state date stored when a client exits. It is not in the prefs file.

Thanks