I upgraded to WMP 10 without thinking. It turns out my Harmon Kardon USB to SPDIF audio convertor does not support WMP 10 and they do not intend to create an upgrade. They product has been discontinued. I don't want to have to buy new hardware. Anyone have any idea how to get rid of WMP 10 and go back to 9? Of course there is nothing on the Microsoft site that is of any use.