I run a two monitor system. When I click Alt+2, the Console Window would open at the bottom of screen one. I would undock it and move it to screen two. For some reason, when I undock it now, the window disappears and I can't get it back or find it. Same happens when double clicking on a track and opening the PRV. It used to open at the bottom of the screen and I would undock it. But, when it gets undocked, it disappears. Clicking on Alt+2 or double clicking on the track does not retrieve the lost windows. Any clues? 

Found another thread on this site where someone had disconnected their second monitor then tried to open the Console. I tried that and it didn't work. But, when I plugged the second monitor back in, there was the undocked Console where it was supposed to be!