Windows 7: Display settings keep reverting

I have an external monitor that I like to use; I configure my laptop display settings to only show the desktop on the external monitor and not on its own screen. However, every time it goes to sleep, when it comes back it doesn't remember the settings and has the display on the laptop monitor instead; I always have to go back to the control panel and tell it to switch back to the external display. How can I get it to remember automatically?

Instead of going to the control panel use Windows + P, it is labeled Projector Only but it doesn't have to be a projector.

http://www.sevenforums.com/tutorials...on-switch.html