Throughout the 1990s, few tech companies could match the sustained growth and regular stock gains that Microsoft delivered: As the software king rode the explosion in demand for PCs, its revenues rose an average 36% a year for the decade -- and its stock climbed from a split-adjusted 60 cents to $59.19. The New Millennium has offered a startling contrast. Microsoft's annual revenue increases have yet to top 16%. And since January 1, 2000, its stock has fallen by more than half, to around $26, as of June 23.

It's true that Microsoft remains a safe harbor in an ocean of tech companies whose performance is uncertain: Its Windows and Office products add $1 billion a month to its cash horde, which now stands at $46 billion. Yet it also seems obvious that jump-starting growth is no longer as easy for Microsoft as introducing a product, spending a fortune on marketing -- and watching sales take off. With its sales approaching $32 billion a year, it'll be hard to regain that magic. As a maturing company in a suddenly slow-growth industry, Microsoft will have to work harder than ever to rescue its stock from lackluster performance.