Microsoft has sold 40 million Windows 8 licenses since the launch of the operating system last month, it has been revealed.
Tami Reller, the finance and marketing head of the Windows division, said that Windows 8 seems to be faring better than better than its predecessor Windows 7, which sold just over 60 million units in the first 10 weeks of sales in 2009.
Although Reller did not specify whether the licenses were upgrades or people buying machines running the new software, it's predicted that the growth will be mainly down to upgrades, which cost around £25 per license.
"Windows 8 upgrade momentum is outpacing that of Windows 7," said Reller, speaking at an investor conference held by Credit Suisse.
The touch-friendly operating system is seen as a way for the software giant to compete against Apple's iOS and Google's Android, whose smartphones and tablets lead the market.
Yesterday it was revealed that Microsoft is considering opening stores in UK next year to add to the 70 it currently operates in the US.
The tech heavyweight is hoping to enjoy similar success to its rival Apple, which opened its first store a decade ago and values its retail experience as medium for building its brand as well as for pushing its products.
There is still no word on how well the Surface is doing, although early in the month Microsoft's CEO Steve Ballmer admitted that sale of the tablet were "starting modestly".