With the one-year anniversary of Windows 7 hitting tomorrow, Microsoft today announced that its latest client OS has sold more than 240 million units in the first year of availability. As always, the company also noted that Windows 7 is the fastest selling operating system in history.

According to Microsoft, Windows 7 is running on 93 percent of all new consumer PCs and has over 17 percent global OS market share; that's more than four times the current market share of its nearest competitor, Mac OS X, which accounts for just 4.2 percent.

Windows 7 has also resulted in huge customer-satisfaction numbers for Microsoft—a nice rebound from the Windows Vista dark ages. Microsoft now has a higher customer-satisfaction score than Apple, according to data gathered by YouGov Plc, and "Windows 7 has contributed more than twice as much to Microsoft's customer satisfaction than \\[the latest OS X release\\] has to Apple's. The annual American Customer Satisfaction Index report showed similar gains for Microsoft.

On the business side, about 90 percent of business customers have plans to deploy Windows 7, according to IDC. Business deployment, too, was a sticking point during the Vista era.

Microsoft notes that momentum for Windows 7 continues through side projects that enhance the OS's appeal. Windows Live Essentials 2011—which includes new email, calendar, photo, blogging, and messaging tools for Windows 7—shipped recently, and Microsoft has seen more than 6 million downloads of the Internet Explorer (IE) 9 Beta, which includes many deep Windows 7 integration features. The final version of IE 9 is expected sometime in the months ahead.