Get back a window, if it disappeared in a second monitor
Sometimes, when you have two monitors connected on your PC, perhaps a computer screen and a TV, an application may disappear in the second monitor accidentally. If the second monitor is closed you have to open it in order to see and drug the application back to the first monitor.
There is however a simpler solution. You can right click on the taskbar button of this hidden application and select the move option.
Note that to have this option available in some Windows versions you need to right click not on the taskbar button itself, but on the small thumbnail preview that appears when you hover the mouse above the taskbar button.
Knowing this simple method that uses native Windows functions, is enough, but you may prefer to use EasyMon, a small freeware application that will arm you with keyboard shortcuts (customizable) to move instantly program panes from monitor to monitor.