The effects of a free upgrade to Windows 10 are starting to trickle in. Available for just over a month, Windows 10 has now captured more than 5 percent market share, according to the latest figures from Net Applications.

In just four weeks, Windows 10 has already been installed on over 75 million PCs. Microsoft is aiming to have 1 billion devices running Windows 10 “in two to three years,” though that includes not just PCs, but smartphones, consoles, and other devices as well.

Windows 10 had 0.39 percent market share in July, and gained 4.82 percentage points to hit 5.21 percent in August. This is the fastest we’ve seen an OS hit 5 percent, and while we’re unlikely to witness growth like that again, we doubt the firsts will stop here.

Unsurprisingly, Windows 10’s predecessors aren’t doing so well. Windows 8 slipped 0.21 percentage points to 2.56 percent, while Windows 8.1 fell 1.71 points to 11.39 percent. Together, they owned 13.95 percent of the market at the end of August, down from 15.86 percent at the end of July. The duo never even passed the 20 percent market share mark (they peaked at 16.45 percent in May), and with Windows 10 now available, they never will.

Before Windows 10’s debut, Windows 7 passed the 60 percent market share mark in June. It’s also likely to see that figure again: Windows 7 saw the biggest drop of any operating system version in August: down 3.08 points to 57.67 percent.

Despite Windows 10’s inevitable rise, Windows 7 will likely keep its title as the most popular OS for at least this year. Windows 7 overtook Windows XP way back in September 2012, and has never looked back, steadily increasing its share even throughout 2015 (it’s still up overall from 55.92 percent in January).

Windows Vista meanwhile slipped 0.02 points to 1.82 percent. This means that in just over a month, Windows 10 has managed to pass not just Windows Vista, not just Windows 8, but both operating system versions combined.

Windows XP somehow managed to gain 0.40 points to 12.14 percent. The free upgrade to Windows 10 doesn’t apply to Vista or XP, so it’s no surprise we’re not seeing large drops right away. That said, it shouldn’t be long now before XP sees single market share digits again, as businesses slowly react to Microsoft ending support for the operating system in April 2014.

On the whole, Windows gained a bit of share in August, up 0.18 points to 90.84 percent. Mac OS X and Linux in turn suffered minor losses, losing 0.13 points to 7.53 percent and 0.05 points to 1.63 percent, respectively.

Net Applications uses data captured from 160 million unique visitors each month by monitoring some 40,000 websites for its clients. This means it measures user market share.

If you prefer usage market share, you’ll want to get your data from StatCounter, which looks at 15 billion page views every month. The operating system figures for August are available here.