When I posted my OpenGL Globe ScreenSaver I wanted to include a screenshot which lead to the question, “How do you take a screenshot of a running screensaver?”
Well, Windows will let you capture screenshots by using the Prnt Scrn key (or Alt + Prnt Scrn to capture the active window). However, when the screensaver is running, as soon as you touch a key or move the mouse, poof! The screensaver is gone.
The trick is: open the display properties (right click the desktop and select properties in Windows XP, Personalize Desktop in Windows 7 I think), switch to the Screensaver settings and select preview. This will run the screensaver in preview mode.
In this mode, you can press Prnt Scrn without deactivating the screensaver. Once you’ve captured your screenshot, move the mouse or press some other key to exit the preview, open up mspaint and paste your screenshot from the clipboard. Enjoy!