Capturing video images

I've been trying to capture images from my videos using printscreen, windows, and real player.

The problem is, when I capture the screen it only copys frames and doesn't copy the actual video images.

I was told to go inside Windows Media player and click on tools>options and then the performance tab. I was then told to turn the video acceleration to none.

At first this worked. but do to other problems I was forced to re-install windows media player. Now when I try to do the same thing, it doesn't work..

Can someone tell me another way to capture the video images??


Later note:

It turns out that I can copy images from downloaded videos, but when I try capturing dvd images it doesn't work...

?
Thanks