Despite Microsoft initially blaming disappointing sales figures on software pirates, the company's Vice President of Windows Product Marketing, Michael Sievert, has now claimed that the piracy rate for Windows Vista is actually half that of XP. In an interview, he said:

While piracy rates are hard to measure precisely, we're seeing indications from internal metrics, like WGA validation failures, that the Windows Vista piracy rate is less than half that of Windows XP today.

Unsurprisingly, Microsoft is putting this down to the fact that Vista is harder to counterfeit. However, some analysts are suggesting that it may be linked to the fact that even pirates expect a stable operating system, and perhaps they choose to use Windows XP over Vista for reasons such as that rather than because they lack the means to pirate it. Of course, another explanation could be that software pirates have actually found a way to counterfeit Windows without being detected, which would also account for the lower rate of WGA validation failures.