Office 365, released this year, brings Microsoft's Exchange, SharePoint, Lync and Office to the cloud, and has been well received, an important step in Microsoft's competition against Google Apps. Perhaps just as important to Microsoft's long-term success is Windows Azure, a service that lets developers build Web applications and host them in Microsoft data centers.
So far, Azure is far behind Amazon's Elastic Compute Cloud in the market for building and hosting websites. But a successful Azure, Gillen argues, could sidestep the Windows Server problem by giving developers a simpler way to build applications. Azure even has an advantage over Amazon in that its platform-as-a-service model abstracts away a lot of the operating system management required of Amazon customers.
At the recent LinuxCon conference, open source advocates said the next innovative Internet businesses along the lines of Google or Facebook will almost certainly be built on Linux.
"But there's nothing that says you can't build that on Windows Azure," Gillen says.
Still, Azure alone would have to be a giant hit to eliminate Microsoft's Web server worries. Azure attracted just 31,000 customers who built 5,000 applications in its first year of existence.
"Public Web servers are a very important dimension for Microsoft to be successful in," Gillen says. "If they can't win there, that does suggest there is a good opportunity for cloud to land on Linux as well."
Microsoft's response: Microsoft declined to answer Network World's questions regarding Web servers, but pointed to a year-old case study showing how the Associated Press uses Windows Server, calling it "an example of a large website betting on Microsoft's web server technologies."
Conclusion: Microsoft isn't going anywhere. The company's wide mix of software will help it stay relevant to businesses and consumers for many years to come. But the rise of mobile devices and companies like Google, Apple and Amazon has come at Microsoft's expense. Although Microsoft revenue is still growing, the days when a single company controls the user interface of nearly every personal computer are long gone and may never return.