Microsoft's Windows 10 got off to a roaring start in its first few days, with its initial usage share handily trumping that of the firm's last free upgrade, Windows 8.1, data from a Web analytics vendor showed.
Worldwide, Windows 10's usage share -- a measure of how active users of the OS were on the Internet, not the number of users or PCs running the operating system -- doubled from 0.3% to 0.6% on the official launch day of July 29, according to Irish metrics company StatCounter.
By the end of Saturday, Aug. 1, Windows 10's global usage share had climbed to 2.5%.
In the United States, the surge of Windows 10 -- which was offered as a free upgrade to most consumers and small businesses running either Windows 7 or Windows 8.1 -- was even more impressive. By Saturday, the U.S.-only usage share of Windows 10 stood at 3.7%.
Windows 10's usage share jump, both worldwide and in the U.S., was dramatically larger than the increase posted by Windows 8.1 in mid-October 2013, when Microsoft offered the revised OS as a free upgrade to those then running Windows 8.
Windows 8.1's usage share topped out at 0.6% -- both globally and in the U.S. -- on the third day after its debut, a fourth (worldwide) and a sixth (U.S.) of Windows 10.
The larger increases were expected: Windows 10's pool of potential upgraders was massive compared to Windows 8.1's, because Windows 7, the dominant operating system both worldwide and in the U.S., was included. And the fact that Windows 10 is, unlike 8.1, a major upgrade -- the latter was a minor refresh -- with a restored Start menu, integrated Cortana and loads of other new features, plays in 10's favor.
Microsoft has also aggressively promoted Windows 10 and the free upgrade with an unprecedented effort that dwarfed any to get users to adopt Windows 8.1 two years ago. This spring, for instance, the Redmond, Wash. company added an app to hundreds of millions of Windows 7 and 8.1 devices that trumpeted the free upgrade, put a one-year time limit on the deal to accelerate adoption and recently began a multimillion-dollar advertising campaign.
Microsoft has only said that there are were 14 million devices running Windows 10 within the first day of issuing the final code, a number that presumably included the approximately 5 million it previously said were using the OS's preview provided to members of its Insider program.
StatCounter measures page views to the sites that deploy its analytics, signaling how actively users of a specific operating system browse the Web.