This solution I owe to my brother – who made me figure this one out for him. My brother is one of you Laptop users that, when home (or the office), hooks up his computer to an external monitor, extending his desktop. This works fine – unless you forget to move every application window back to your main desktop before disconnecting the extra monitor. Then what do you do ?
If you’re still at home (or the office) then it’s no “biggy”, but if you’re on the road somewhere, suddenly realize that your PowerPoint presentation is showing on the “other” monitor… What then ?