Consider the following scenario:
On a Windows 7 laptop with hybrid graphics
Connect a DVI and a VGA monitor
Connect a USB keyboard and mouse
Set the Close Lid action to "Do nothing"
Close the lid of the laptop screen and to use only the external monitors
On the keyboard, use Windows key +P to try and duplicate the display across the DVI and VGA displays
When you try to clone the display across two video cards, it is not possible and will show the display only on the DVI monitor.
On a Windows 7 laptop with hybrid graphics
Connect a DVI and a VGA monitor
Connect a USB keyboard and mouse
Set the Close Lid action to "Do nothing"
Close the lid of the laptop screen and to use only the external monitors
On the keyboard, use Windows key +P to try and duplicate the display across the DVI and VGA displays
When you try to clone the display across two video cards, it is not possible and will show the display only on the DVI monitor.