The one with the dll is a bit quick and dirty. There is a good german “how to disable Windows XP/2000 Services” guide http://www.kssysteme.de/s_content.php?id=fk2002-01-31-3823
A quick google search brings up this site. Maybe it is usefull(did not read it completly) http://www.overclockersclub.com/windowsxpservices.shtml
But be carefull, if you not know what you doing, it could affect the “behavior” of your Computer!