After exiting from an extended desktop mode under Windows 7, you will be surprised to see all windows that were left opened in second monitor, back in the primary monitor. To leave extended mode hit the keyboard shortcut Win + P and select Disconnect Projector. But this is not all.
Windows 7 includes two new shortcuts; Win + Shift + Left Arrow Key & Win + Shift + Right Arrow Key to move windows between multiple monitors. Thus, making 3rd party apps, such as, MonitorSwitch, useless when it comes to dual-monitor setup.
The above mentioned two hotkeys only work in Extended mode. Lets say your windows got misplaced when you were in a single monitor mode, now these two hotkeys will not work. You could either use the following method which worked in old operating systems as well,
Select the hidden or misplaced windows from the taskbar, hit Alt+Space, press M, and finally press any one of the arrow keys (doesn’t matter which one you press) before moving the mouse.
or use another quicker and memorable method which only works on Windows 7.
Hit Win + P to bring up display options, select Extend and use the Win + Shift + Left Arrow Key hotkey to bring back the off screen windows. Now hit Win + P once again and return back to single monitor mode.
Windows 7 does a great job in treating the off screen windows, so you might not fall in such situations frequently, but when you do, lose no hope.