The day before opening the Windows Hardware Engineering Conference (WinHEC) 2004 trade show in Seattle, Microsoft announced that it has sold 210 million copies of Windows XP, most of which were bundled with new PCs. However, the company also noted that XP use is far higher than that number because its sales figures don't include copies of XP that are bundled with new machines under corporate licenses. 
  
Microsoft last released XP sales figures in July 2003, when the company announced that it had sold 130 million copies of the OS. Microsoft notes that it's now selling about 10 million copies of XP every month and that sales are accelerating month over month; last year, the company averaged 6 million copies each month.
  
Although Microsoft's efforts to prep XP Service Pack 2 (SP2), a major upgrade, have stalled in recent days, the company has released an impressive number of XP upgrades since the OS first shipped in October 2001. In addition, Microsoft has augmented the original releases of XP Home Edition and XP Professional Edition with other software versions, including XP Tablet PC Edition, XP Media Center Edition (XP MCE), and various releases for 64-bit hardware.