dilla, check your replay before extracting it, as in watch it, take note of when you want the recording to begin, and then when you want it to stop, for example, a BnG shot, I would start the recording about 1 seconds before the pwoer bar starts, and end it when the damage taken shows, or when the grav blows up, remember and extract the video to a good resolution, I personally extracted it to the resolution I play the game with.
This tutorial will let you know all the basic stuff, and if you don't understand anything, just give me a shout on MSN or something and I will try to explain:
http://worms2d.info/Creating_a_Worms_movie