When I open a new document or image it isn't full screen but a little square up in the corner that I have to drag down & expand. I'm using PSE 15 & it just started doing this. I must have accidentally changed a setting but I don't know which one or how to fix.
Go to Edit>Preferences>General. (Ctrl+K) Uncheck the Allow Floating Documents in Expert Mode box.
Such a simple fix, thank you.