Instructions
Open "RollerCoaster Tycoon 3."
Click on the roller coaster you would like to make a movie of. This will start the ride.
Press and hold "CTRL," "Shift" and "F11" simultaneously. The game will slow down to frame-by-frame mode as the movie is recorded.
Press "CTRL," "Shift" and "F11" to stop the movie.
Close the game. Click "Start," then "My Computer," then "My Videos," then "RCT3." Right-click the video and click "Open" to view your movie.