Windows 10 passed a pair of milestones over the last two weekends, breaking the 10% usage share bar 10 days ago, then the 11% mark on Sunday, according to measurements by Irish analytics firm StatCounter.
More importantly to Microsoft's plans for the new OS, Windows 10's growth has kicked back into a higher gear, pushing week-over-week gains to a level not seen since late August.
By Monday, 90 days after Windows 10's July 29 debut, the operating system's usage share -- an indication of online activity because it's based on website page views -- had topped 10% on two occasions and edged above 11% once.
Those spikes all came on weekends, when Windows 10 has been used the most, a trend common to any new edition of Windows. First adopters are almost exclusively consumers, with usage spiking on Saturdays and Sundays when they're free to use their home PCs rather than being locked into an older OS on a corporate machine.
Peaks notwithstanding, StatCounter's data also showed a trend more critical to Windows 10's long-term success: A second "wave" of usage growth.
Computerworld has charted the average week-over-week increases in usage share for Windows 10 since its debut, calculating the results using seven-day rolling averages to eliminate daily fluctuations. A month ago, that showed a two-week growth wave which, after hitting a trough on Sept. 20, crested on Sept. 26 before slowly falling to the next low point on Oct. 3.
A second and more sustained wave of week-over-week gains began on Oct. 11, peaked on Oct. 22-23, and doesn't appear to have bottomed yet.
In the latest wave, the largest week-over-week gains -- more than half a percentage point -- were Windows 10's biggest since around a month after its launch, when it was being snapped up by consumers.
Charting usage share for Windows 10 is one thing, but explaining it is quite another: Outside Microsoft's HQ, reasons for the increases are only guesswork.
It may have simply been a more active stretch for Windows 10 users -- more online activity, in other words -- or due to consumers swapping out older PCs for new systems that came equipped with Windows 10. Or it may have signaled that Microsoft continues to pull the upgrade trigger on more machines running Windows 7 or Windows 8.1.
Users of those operating systems have been allowed to "reserve" an upgrade since June. Microsoft then pre-loads the Windows 10 upgrade bits -- as much as 6GB worth -- to those devices, but staggers the notifications displayed on customers' computers to alleviate server overload.
The company has been silent on the mechanics of the rate at which it has upgraded customers' PCs, and mum on how long the process of pushing Windows 10 to those who asked for it will ultimately take.
Microsoft has been trying other tactics, however, to boost Windows 10 adoption among consumers with older devices, and the upsurge in usage may have been caused, if in part, by those maneuvers.
The most controversial of the alternate approaches has been to pre-load the upgrade bits on PCs whose owners have not requested Windows 10, then nag them into triggering the migration using Windows Update. In some cases, the company blocks users from installing security updates without first upgrading to Windows 10.
Earlier this month, Microsoft set Windows 10 upgrades to automatically download and begin installation on Windows 7 and 8.1 machines -- a process people could cancel if they paid attention -- but then backed away from the practice when it became public, saying that it had been a mistake.
Other explanations for the upsurge in usage may include the partnerships that Microsoft struck with several large Chinese companies this fall, including Baidu, the People's Republic of China's largest search engine, to promote Windows 10 and make upgrading PCs there simpler.
A counter on the Baidu website dedicated to Windows 10 upgrades -- which leads to a download of the "Windows 10 Express" application -- now stands at over 686,000. Three weeks ago that counter tallied about half as many downloads of the app, which checks the PC for upgrade eligibility, runs a system scan to ensure the machine is able to handle the new OS and then begins retrieving the upgrade.
Windows 10's usage share remains higher than Windows 7's at the same post-release point, and the gap, once closing rapidly because Windows 7 launched later on the calendar and accumulated impressive gains around the 2009 holidays, has recently widened. As of today, Windows 10 was ahead of Windows 7 by about 1.4 percentage points, or three to four weeks' worth of growth.