use schibo's Audio plugin and disable the speed limiter (F9) it should run ok. Also, for the OS, it depend of the drivers, there is some drivers that makes it run faster and they are for win9x. And, too, since it's a Celeron 533, you can try win98se, it will maybe run better.
I could have told that in french to you but since the forum is in english , I must say it in english
