I'm using WMP10 inmy 2nd system to utilize PC audio. I finalize had things configured to produce what I thought to be enjoyble sound quality, especially considering the approach. I was having some trouble ripping some Cd's and saw that a WMP11 beta version was out and thought that might solve the problem. I downloaded it, set it up and I liked the interface a bit better etc... and I thought OK this is promising. I played on of my favorite songs first and YUKKKKKKK, it sounded bad, like I took two steps back. Soundstage was screwed up, transparency diminished and that was all I needed to hear.
I went to check the settings etc... but no fix worked. I hit system restore so fast and prayed things would go back to normal, luckily they did...THANK YOU GOD. Now I realized most aren't using WMP or microsoft based software for the main or maybe 2nd or 3rd Pc audio system playback but if you use WMP in any compacity for music don't mess with that Beta versionor maybe the finished WMP11 for that matter. I actually am getting good results using the WMP10 method running through my Mccormack DAC, I was suprised how decent it sounded as I fully intended to upgrade the playback elements to something else but it turned out to be very satisfying.
So just my 2cents and not meant to bash microsoft products as I am satisfied with WMP10 but someone totally botched the SQ for the Beta upgrade, that was horrible.