I have a Windows 8.1 laptop with Intel HD graphics and three displays: 1) The laptop, 2) mini HDMI connection to external monitor, 3) USB3 video adapter connected via HDMI to external monitor. All three displays work normally except... Sometimes I seem to type a special key combination that makes the next number that I type move the active window application to the display with the corresponding index. i.e. hitting a 2 moves the current application to the second display. A 3 moves to third etc.
I cannot figure this key combination out or where to turn it off. It's driving me nuts!!!