It might be a little, very little even but something interesting can be spotted in the Steam user surveys. The number of Windows 10 installs are on the decline, and Windows 7 seems to be rising. 

According and as spotted by neowin, this decline is mostly found in the 64-bit version of the OS rather than the 32-bit iteration.

Interesting finds are these:

• Windows 7's user base climbs to 36.99%, which is an increase of 0.85 percentage points.  Yet all other versions of Windows lost some of their user base market share.
• Microsoft is still the big daddy iN OSes though, 96.12% of surveyed Steam users makes use of some sort of Windows. However, Apple's OS X/macOS grew to 3.11% and Linux progressed to 0.74%.
• Most users have 8GB of system RAM and their display resolution for primary displays remains to sit level at 1920x1080 and 3840x1080 for surround view respectively.

These surveys are optional though, so the validity remains a little iffy. Then again, there is no PC Gaming user-pool bigger than Steam.

Windows 10 Drops a Bit in Favor for Windows 7 on Steam