Is there a quick way to return to the desktop if that's where you were when you launched a program and close it? For example, several times now I have been in the desktop and tapped on a .pdf or .jpg. The metro apps for these files opens and displays them. I then hit escape or swipe from the top and the app will close but it returns me to the start screen, not the desktop. Is there a simple keystroke or gesture that I'm not aware of to do this?