everytime when i copy a flv file from another pc, my windows media player, vlc player, kl codec player cannot play that file..i have tried several players but it isn't working? tell me how to play those flv files...asap plz

If VLC player is not able to play FLV files then I doubt you are trying to play something different. Or may you consider upgrading your VLC player to something latest or also try another player named SMplayer.