Microsoft has sold four million upgrades for Windows 8 since its launch three days ago.
Speaking during the company's BUILD 2012 conference, CEO Steve Balmer said enthusiasm for the new operating system was "very high."
Believed to include individual purchases as well as units expected to sell by retail stores, the sales are of similar comparison to Apple who shipped three million copies of Mountain Lion just four days after launch.
Microsoft however, will be seeking a larger push in sales over the coming weeks with Balmer revealing "tens of millions" copies have already been sold to its OEM partners.
Unveiled last week, the world’s first copy of Windows 8 was sold in Auckland, at Harvey Norman’s Wairau Park store on the North Shore.
Kiwi Greg Daniel was the first person to get his hands of the software, after pre-ordering his copy of Windows 8 Pro from the store as soon as the exclusive pre-order offer opened on 23 October.
Have you got your Windows 8 copy? Tell us your thoughts below