At the annual Microsoft Worldwide Partner Conference, CEO Steve Ballmer announced that sales of Windows 7 licenses crossed the 400 million mark. In June last year, the figure stood at 150 million, and by October, it rose to 240 million. With sales of 400 million license in under two years, Windows 7 is the fastest-selling operating system in history. On a related note, Microsoft announced that 100 million copies of Office 2010 were sold since its launch.
Source: Engadget