Firstly, please perform a
system restore and see how it works.
If system restore cannot help, please let us know the following:
1. Do all the .mp3 files have the same issue?
2. Does Windows have sound?
Meanwhile, please try the following:
1. Disable all Plug-ins and see how it works.
2. Double check your speakers settings in Windows Media Player.
Hope this helps.
TechNet Community Support