Vendor cites strong PC sales, defends uptake of OS despite big drop in client revenue.
Bill Gates: Microsoft Readies Next-Generation Operating System for 2009.
According to Microsoft's timeline, XP is on its way to becoming an ex-operating system.
The world's largest software maker introduced Windows Vista in January with the plan to phase out sales of its predecessor, Windows XP, by January 30, 2008.
Microsoft has sold nearly 40 million copies of Windows Vista so far, Bill Gates told a crowd of hardware developers Tuesday.