Your method seems to be wrong (no "control center", only security center, and security center doesn't seem to allow me to disable automatic updates within a current XP session... which isn't what I want... I want to disable automatic update and don't want XP SP2 to warn me that automatic update is disabled everytime I boot up), and I don't think you understand my question.
Either you don't understand my question, or I don't understand your answer.