If you are using Mac OSX & like using QuickTime player, check this list also .avi ~ sound but no video in Quicktime (Click on blue link). I highly recommend Perian plug-in codec, and also VLC & MPlayers just in case. MPlayer I'd recommend the OSX beta version. Depending on the file, some I set to open with VLC, some with MPlayer, some with QuickTime Player.

Thanks guys ,but I am using windows XP.

You can use VLC player with XP - I do. Check out the link that I gave you in post #2... it has a further link for downloading VLC. VLC is a free media player, with codecs built in to play most file types. If VLC can't play the file, chances are it's a bad file.

You still haven't told us what client you're using, or even what file format you're trying to play

One month ago and still the problem has not been solved . . . is there a simple yea or nea solution anyone ?

Problem : Downloaded files will not open or play in itunes .

Simple answer : what's the problem and how is it solved ?

Thanks.