i downloaded some videos from limewire why wont they play?

Answer 1

Because most of the so-called "videos" listed on Limewire are bogus items and are actually virus and trojan horse programs designed to turn your computer into an email spam Zombie so they can sell your computer's access to spam houses.

Answer 2

Possibly, you are using the wrong player for the file type of the videos, it has happended to me already...try using a different player.