Microsoft says that Windows Vista sold 20 million copies in its first month of release, besting Windows XP's 17 million copies in its first two months. Engadget softens some of the press release spin, noting that 239 million PCs sold globally in 2006, so 20 million isn't a shock. But Microsoft Watch dismantles the original claim with a detailed editorial.
Microsoft Watch says that Microsoft has counted sales beginning late last year before the general-public launch. The editorial also notes that license sales in the channel shouldn't count -- the "shipped" versus "sold" debate. Finally, analysts don't agree with the total.