Just as Windows client software dominates the desktop, Windows server software makes big bucks in the enterprise IT market. IDC numbers from the second quarter of 2011 show that Windows Server accounted for "45.5% of overall quarterly factory revenue and 71.0% of all quarterly server shipments." The rest goes to Unix, mainframes, Linux and other platforms.
While not as impressive as Microsoft's desktop share, Redmond can count on a steady revenue stream from businesses using Windows Server to host Microsoft applications such as Exchange and SharePoint, and non-Microsoft applications from the likes of Oracle.
Microsoft's real server struggle is in the Web server space. Although Microsoft's IIS Web server software that's used with Windows powers more than 60 million websites, that only accounts for 16.8% of the market, which is dominated by the free software Apache, according to Netcraft.
Also according to Netcraft, nine of the 10 most reliable hosting companies run Linux or FreeBSD, with just one using Windows. Surveys by W3Techs show Linux and other Unix-like OSs account for 64% of websites.
These numbers wouldn't include private intranets, but the fast-growing world of the public Web is one where Microsoft would like a stronger foothold. Few people actually use Linux desktops, but Linux enthusiasts will tell you that when you point your browser to Google or Facebook, you're using a Linux-powered service.
Microsoft's Web server problems date to the early 2000s when security holes gave the company's technology a bad reputation, Gillen says.
The technology has improved, but Linux and Apache are free, and therefore hard to beat.
"I think they've got the technology there, they're marketing it pretty well," Miller says. "The [Microsoft] server guys are running on all cylinders and understand how these things are working."
The Web has been crucial to our daily lives for years, but is taking on even greater prominence as cloud computing technologies move consumer applications and business services from home computers and private data centers to online services. But if Microsoft can't build the servers that power third-party websites, the company can build clouds of its own.