I "Reset Module Layout" in SGP. This is apparently a minor mistake on my part. What I will call the "module docking window" on the left side of the SGP desktop disappeared along with the docking modules that resided there since I started using SGP a couple months ago. Instead, all docking modules were launched on the SGP desktop in what now appears to be a single "Image Window."
I have closed all docking modules that I don't want, but now they simply reside on the main Windows desktop and not the SGP desktop. I cannot find a way to reestablish the docking module window on the SGP desktop.