windows media player problem

...i got this problem with media player, when i open a mp3 file, the file open and plays but without sounds, my computer "volume" isnt mute and when i open the files with other application (like VLC player) it has sounds........

Check the volume of WMP itself. It might be muted or turned down to 0 volume.

already tried that,but still no volume

When playing in WMP, have you turned your computer's volume all the way up? It might just be playing more softly than in other programs. Other than that, I don't know.

its always up for me(max)........all including the control pannel,

You're probably lacking an audio codec. Try this one.

But in all seriousness, I hate WMP. Get iTunes or Winamp. They pwn.

I don't mean to be demeaning or stupid, but have you tried restarting your computer? 90% of the time I have, or am consulted on, a computer problem (especially audio related) a restart fixes it. Also, if all else fails, copy your hidden user files (Local Settings, Application Data in My Documents in XP, AppData in your user folder in Vista) and all your media to a secondary hdd and reinstall Windows. Make sure you save a list of all your installed programs though.
I always find that reinstalling Windows on a regular basis (once a month for me) keeps everything working quick and easy. In fact I save all the MSIs (installers) for my favourite programs and all my media to a secondary hdd, and can have my system right back to where it was in about 3 hours, 4 if I install all the MS updates.