Stock futures fell hard ahead of Tuesday's open, tracking overseas losses and following a sudden transition in Microsoft's top management. Dow futures were down 63 points and pointed lower. Nasdaq 100 futures fell 18.25 points and S&P 500 futures were 7.8 points lower. Microsoft (MSFT) traded down 3% in premarket action, following the sudden resignation of Steven Sinofsky, head of the company's Windows division. Several news sources said Sinofsky