WMP 11 Not Playing Codec Error

[Coach17]

I have WMP 11 and it has all of a sudden stopped working. When I open a music file MP3 WMP 11 opens and it says it is missing a Codec file and can go to web help and when I get there it says there is nothing to download. I re-installed WMP 11 and still get the same result. I have also discovered that my Windows sounds are not playing. I went to the sounds in Control Panel and when I highlight a windows sound the small arrow is not highlighted to test the sound. I checked my speakers and they do work. So far only in ITUNES
I do have ITUNES and that works fine. Any idea what is wrong?

Thanks for your help.