I had an odd issue recently. I was editing some code in Atom and ended up closing my laptop and setting up somewhere else. When I opened my laptop I could see Atom running but when I clicked on the app it would not show it. I tried alt-tab etc and still no luck. I tried restarting and the same issue. I tried to uninstall and reinstalling and the same issue. What ended up working was this:
Open the Windows Task Manager.
Select Atom and click on it which will expand it to show a subprocess. Right Click on the sub-process, and then select Maximize.
Now I can see the editor 🙂