I had this same problem in my old computer before. The problem is that when installing S60 SDK, it doesn't work in win XP. I have forget the solution, who it is possible to install "S60" to win XP. If I remember correct, the idea was putting some commands to win path.
Does someone noticed this same problem and what was the solution.
ps. When installing to win 2000 everything goes fine :) but xp has became my nightmare...