Another day, another new Windows 10 preview for PCs

As Microsoft inches closer toward releasing to manufacturing Windows 10, it is continuing to roll out near-final preview test builds to its Windows Insiders on the Fast Ring.

On July 9, Microsoft made yet another of those previews available for testing on PCs and tablets: Build 10166. Microsoft also is pushing out a corresponding software development kit (SDK) preview today.

To be clear, this build is not the build Microsoft plans to designate as RTM. It's close, but not that build. I'm not sure exactly when Microsoft will hit the RTM milestone. It should be soon; my sources have told me the plan remains some time in "mid-July." Some had been expecting Windows 10 to RTM today, July 9, but that's not happening, my contacts say.

Today's build, like a number of those Windows 10 preview builds released recently, is mostly about bug fixes and polish. There are no brand-new features in the build.

As part of today's build for testers in Seattle only, Microsoft is making available a preview of its coming paid-Wi-Fi app for download from the Windows Store. The company will roll this out to all in the U.S. later, officials said.

Last week, Microsoft released in rapid succession three different preview builds to Windows 10 Fast Ring Insiders.