It's easy with the right software. If your movie is in AVI format, you can import it into Movie Maker (if you have it) and stop where you want and save a still image.
Most modern video editors have this function.
hi
how to capture a image from a movie?i.e.stopping the movie and saving that picture to harddrive and view afterwards
sundaram

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic