I've been using WMP11 for a while now with no problems.  Today I had no sound. I was prompted with MS error web site to download a upgrade for WMP 11.  How ever I believe it was for Media Center which I don't have.  Unfortunately the download did not repair the issue of no sound.  I have since rolled back WMP 11 to WMP 9 and still no luck.  I also downloaded Expl 7, thinking there might be a file to remedy the sound problem. Still no luck.  I love my sounds, so what ever help anyone may be able to provide would be greatly appreciated.  I tried the codecs web and drm rights with negative results as well.