Windows 7 lets you connect your computer to a projector to give a presentation on a large screen. This is called projection mode or presentation mode, and pressing Windows key + P should bring up a popup dialog that allows you select one of four modes: Computer Only, Duplicate, Extend, or Projector Only.
Problem: You've installed Windows 7 on your laptop and you've connected your laptop to a projector. But when you press Windows key + P the popup dialog doesn't appear.
Suggestion: You might have the standard VGA driver installed instead of a hardware-specific display driver. The default VGA driver doesn't support projection mode. Check in Device Manager.
Mitch Tulloch is a seven-time recipient of the Microsoft Most Valuable Professional (MVP) award and widely recognized expert on Windows administration, deployment and virtualization. For more tips by Mitch you can follow him on Twitter or friend him on Facebook.