.RAID3N. 0 Newbie Poster

Just found this site and thought everyone here might be able to help me!
I am using a Toshiba Satellite L25 S1193 and just got a desktop monitor to hook up to the VGA output. I managed to get both screens up and running partly how I would like them to. My ideal setup would be to use the desktop monitor as my primary monitor. I tried to move the start menu over to that monitor, but when I open up programs, they open on the laptop screen. I tried to make the desktop monitor my "primary monitor" under the display settings, but found that it was shaded and not an option. Can anyone shed some light on why I can't use it as my primary display? Or a solution? I want to be able to close my laptop and still use the computer. Thanks a bunch!