More than one in every five gamers on Steam is already using Windows 10.

Valve updated its Hardware & Software Survey today for September 2015, and there’s more good news for Microsoft. Windows’ overall share slipped slightly on Steam, but Windows 10 adoption has managed to pass Windows 8.1 in just two months.

In the first month, Windows 10 adoption on Steam passed Windows 8, Windows Vista, Windows XP, Mac OS X, and Linux. With Windows 8.1 now conquered (we gave Microsoft till the end of the year, but apparently it only needed another 30 days), only Windows 7 is left.

Here is the September 2015 operating system market share list for Steam:

  • Windows 10: 24.87 percent
  • Windows 8.1: 19.08 percent
  • Windows 8: 2.63 percent
  • Windows 7: 45.99 percent
  • Windows Vista: 0.54 percent
  • Windows XP: 2.56 percent
  • Mac OS X: 3.23 percent
  • Linux: 0.94 percent

Put another way, among Steam users, Windows 10 already has more than half the adoption of Windows 7, the most popular option. We doubt Windows 10 will take first place this year, but at this rate, it’s certainly a possibility.

Breaking down the numbers even more, here is how each operating system version fared:


Between August and September, Windows 10 jumped a solid 7.85 percentage points (from 17.02 percent to 24.87 percent). These gains have to come from somewhere: Windows 8.1 dropped 4.82 points (from 23.90 percent to 19.08 percent), Windows 8 slipped 0.25 points (from 2.88 percent to 2.63 percent), and Windows 7 fell 2.55 points (from 48.54 percent to 45.99 percent), Vista dipped 0.12 points (from 0.62 percent to 0.54 percent) and XP slipped 0.20 points (from 2.76 percent to 2.56 percent).

On the whole, Windows still dominates Steam with over 95 percent share. Nonetheless, Mac and Linux saw minor gains in September, up 0.01 points and 0.02 points respectively.

It’s impressive that Windows 10 has managed to pass Windows 8 and Windows 8.1 combined in just two months. Gamers are quicker to adopt the latest and greatest from Microsoft, as it often means better support for their rigs and games. If everyone upgraded this quickly, Microsoft would have no problem of reaching its goal of 1 billion Windows 10 devices in three years.