AT Seattle’s baseball stadium this Friday, 16,000 Microsoft employees will gather for one of the world’s biggest birthday parties. Microsoft is 30, and Bill Gates wants to celebrate.

Gates was just 19 when, in August 1975, he and his school friend Paul Allen registered a partnership in Albuquerque, New Mexico, that they called Micro-Soft.

Amid the anniversary festivities, Microsoft’s founder and chairman will set out a confident vision of the software giant’s future. The company is about to embark on its busiest product-release schedule for years, and expects to generate billions of dollars in new sales.

Next year it will introduce a new, more secure version of its Windows operating system called Vista, as well as an update to its Office suite, which includes Word and Excel. Before that, it will launch the Xbox 360 gaming terminal, and a new version of SQL Server database software for the business market.

In a world increasingly connected by broadband internet technology, Gates will point to the central importance of software — a belief that has underpinned his company’s phenomenal growth.

But even as Microsoft’s employees listen to Gates’s optimism, it will be hard for them to ignore their doubts. There are many who fear that the rewards of the next few years will struggle to match those of the past.

Put simply, Microsoft is no longer a hot stock. Investors are worried about its slowing sales growth, which dipped below 10% for the first time last year.

“People just think there’s no growth,” said Heather Bellini, an analyst at UBS, the investment bank.“The apathy level is high.”

In the 1980s and 1990s, the company’s soaring share price turned thousands of its programmers and sales people into millionaires. At just above $26, Microsoft’s share price is pretty much where it was in 2002, or even in 1998. It has missed out on the recovery enjoyed by other big technology companies in the Nasdaq index.

That matters partly because it hits staff morale, but also because it damages Microsoft’s ability to hire the best programming talent. George Colony, chief executive of Forrester, a technology research firm, said: “One of the biggest mistakes ever was to move away from stock options. If you give up stock options, you’re not going to get the hottest programmers from MIT (Massachusetts Institute of Technology) and Caltech (California Institute of Technology). “There’s a brain drain now from Microsoft to Google.”

This was graphically illustrated in July, when Kai-Fu Lee, a speech-recognition expert, quit Microsoft to join the search-engine company. Mark Lucovsky, another of Microsoft’s most highly valued engineers, also defected to Google, provoking apoplexy from Steve Ballmer, Microsoft’s chief executive.

The rise of Google is arguably the biggest competitive threat Microsoft has faced but it is far from being the only serious one. For instance, the growing use of “open source” Linux software is a big challenge in competing for corporate customers.

Microsoft is also keen to move into consumer and entertainment markets, a growing opportunity in the broadband era. However, Apple’s iPod and iTunes have wiped the floor with the Windows Media Player in the fast-expanding field of digital music.

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