Close to half of Steam gamers are running on Windows 10, with the percentage of people on Microsoft's latest OS rising 3.41 points to 44.46% since last month. May was the first month Windows 10 was greater than Windows 7 and the Steam user base continues to shift towards the newer OS.
The above-average increase in the past month can at least partially be attributed to Microsoft's free upgrade period, which is coming to an end on July 29. As such, another large increase will likely be seen for this month.
Windows 7 has 36.97%, Windows 8/8.1 has 12%, OS X has 3.6%, and Linux sits at 0.8%.