...how do i change file type? when i try to watch it is in a audio format and i dont know how to change it and if i had to download something i want it to be free can anyone help me plz
It will most likely work with vlc player. VLC is the best player out there. It will play almost any video http://www.videolan.org/vlc/ If you don't want another player for some reason, you could also try installing a codec pack http://www.free-codecs.com/download/K_Lite_Codec_Pack.htm
try VLC media player, it plays most things (just google it).
There are also a few codecs packages for windows media player, you can try the CCC pack which is quite good