Microsoft today shipped a new Windows 10 build to its Insider testers, a refresh focused on bug fixes and improvements that contains a clue that signaled the first update for most users since July is imminent.
Thursday's build, labeled 10586, is the successor to version 10565, which Microsoft issued more than three weeks ago.
Build 10586 is a polish on last month's Insider update, and introduces no new features, hinting that it is among the last before Microsoft gives the code the green light for mass distribution.
"This build is really focused on bug fixes and general improvements," wrote Gabriel Aul, engineering general manager for Microsoft's OS group, in a post to a company blog today. "We've been loving this build in our internal rings as it is very fast and smooth, and makes a great daily driver."
While Aul's word choice pointed to build 10586 as the release candidate for Microsoft's first-ever update to Windows 10, a more significant cue was the omission of an on-screen watermark, which has appeared on earlier builds to mark not only the build number, but that it the code was for evaluation only.
Build 10586 has no such watermark.
Microsoft scrubbed the watermark from Windows 10 previews in the summer as it pushed towards launch. When it paused Insider build deliveries July 13 -- with Aul saying then that the company was "very close" to finalizing the OS -- it wiped off the watermark. Only after the July 29 launch, and the resumption of Insider builds to testers on Aug. 18, did the watermark return on preview program participants' PCs.
Rumors have circulated for the last week or more that Microsoft would issue Windows 10's first update, code named "Threshold 2," in the first few days of November. When that stretch came and went, the chatter shifted to pegging Nov. 10, which is also Microsoft's Patch Tuesday for the month.
Unlike with Windows 10's debut, Microsoft has not revealed a release date for the update ahead of time, nor said what nomenclature it will use to identify this update and others in the future.
In some places, Microsoft has tapped the initial Windows 10 build as "July 2015."
If build 10586 does become the release candidate for the update, it will be a milestone for Microsoft: The company has committed to generating multiple refreshes of the OS annually -- two to three times a year -- and this will be the first to automatically deploy to most consumers and many small businesses via the "Current Branch," one of three post-preview tracks the company will maintain for Windows 10.