Switching from laptop to external display?

I have a new HP laptop running windows 7, my tower was damaged and I have a beautiful wide screen monitor that I want to use. My question is, how do you watch a movie on the widescreen monitor and use the laptop for something else??? This has been making me nuts. I have gone into display options and the only choices I have are extend or duplicate? Anyone know how to do this? I hit detect and identify and it does nothing. Have also done right click on desktop, also gone into Catalyst Control Center and just can't get this to work. It mirrors and extends, that's it! And why doesnt the PC recognize the monitor? Thanks in advance.