Take screenshot from windows media player

1 – Open Windows Media Player
2 – Go to Tools > Options > Performance
3 – click on “Video Acceleration“, drag the slider to none
4 – Click Apply and then OK
5 – Restart WMP if it’s not restarting by itself.
6 – Open the movie you want to take a screenshot of, fast forward to the place that you want one of, then click Print Screen button.
7 – Open MS Paint / Adobe PhotoShop, Corel Paint or whatever program you are thinking to use and paste it.
8. You should have now the printscreen of the movie.

A second method is referring to Overlays:
1. Open Window Media Player
2. Go to Tools > Options
3. In Options, click on Performance Tab
4. Click on the Advanced Button
5. Uncheck “Use Overlays”

Don’t forget to roll back the changes when you’re done :)