I was trying to capture a still from Windows Media Player and use it in one of my blog posts. What I got was a black square! Why did this happen? It seems this has something to do with video acceleration used in Media Player. I was able to find the solution while going through windows media player help file (search for capture).
Very simple actually. When playing the video or when it is paused just press Ctrl and I button together (Ctrl+I). Windows media player then throws up a save as screen and you can save the screen shot as a JPEG file. Pretty neat!
I did a bit of further research and noticed this. If “use video mixing renderer” option under Tools=>Options=>Performance=>Advanced is checked then Ctrl+I works, otherwise plain old screen print works!