I'm running windows xp... but I don't have the same power options properties window that you're showing in your screenshot. I'm missing the "Advanced Settings", "Beep/Alarms", and "Suspend/Hibernate" options, but I have all the others. Unfortunately none of the others have cpu management

I've also been having the problem of it running at full speed (which is rather noisy) whenever I have just music or even sometimes when nothing is running. I noticed this last night as I tried to sleep. Is it possible that it is not judging correctly what my processor speed should be?

I've looked into some programs that will control it (mainly SwitchSpeedXP) although when I installed it I had the same problems. SSXP has an option to detect maximum CPU speed and many times it would show me 800MHZ (on a 2GB machine). Is there a windows service or application that controls it normally that I should disable?