MS knowledge base is a help
In Windows Media Player, you can play a video file in slow motion or frame-by-frame (frame-stepping) by using the controls in the Play Speed Settings Enhancements pane. To play a video at variable speeds, do the following: 1. While the video is playing, on the View menu, point to Enhancements, and then click Play Speed Settings. 2. In the Enhancements pane, do one of the following: • Move the Play Speed slider to the speed at which you want to play the content, or click the Slow or Fast links. • Click the Fast Forward or Rewind button to change the playback speed.