Sum movies have no sound

lately most of da movies have no sound only when i convert with covert x they do or when converted to mp4
Answer #1
Sound card drivers updated? Codecs installed? What player are you using to play the movies, and which format are they?
Answer #2
Maybe you need the latest codec-pack,for ex.CCCP or K-lite.You can google it.
Answer #3
windows media player but it plays sum movies with sound but also when i put movies on hard drive and connect it 2 a media player for my tv no sound avi
Answer #4
check convert x audio setting. cause your problem no sound after convert.