How do I get still pictures from a movie file?

[Koosh]

Just wondering... I have a video (mpeg) that I want to take a "screen shot" of so I can mess with it in photoshop... how do you go about doing that?

[Gotenks]

the magical print screen button

[Koosh]

I tried that... I paused the video on what I wanted, did the print screen, then when I went to "paste" what it did was as soon as I hit "Play" on the media player, the thing I Pasted changed with the file... So whatever I paste won't stay that way... as long as the original file is still open it changes with that file, if it stops, then I just get a black screen where it was supposed to be in the paste thing...

Sorry if that doesnt make sense, but that doesnt work for some reason...