The main problem seems to be that when, for example, I double-click on an mp3 in explorer, it takes longer to actually access windows media player 9. Thge song then starts to play, but with no sound. If I hit "stop" and then hit "play", the song starts with sound and no problem. I can live with the slow start-up process, but the re-clicking is a pain. Maybe Cadfael's answer is the only solution, but I'm loathe to re-install windows xp pro back over itself - will this cause me any problems?
Thanks in advance for any advice.