Automatic display selection

"It works fine for me on my laptop with Windows XP (using a Mobile Intel 965 Express chipset with integrated graphic card). When I connect the laptop to an external monitor, this monitor becomes the primary and the laptop screen becomes secondary.

I suggest you update the graphic card drivers, as it's a feature managed by the drivers. It used not to work correctly for me until an updated driver came out.

Otherwise, you could have more luck with the Profiles feature of Ultramon."