Microsoft is rolling out a new Windows 10 "Redstone 2" test build for PC and Mobile to Windows Insiders in the Fast Ring.
Build 14915, available today, August 31, is mostly a collection of fixes, as it is still early days in the Redstone 2 development process.
In today's build, among the fixes for PC and phone users are ones for Cortana's text-to-speech functionality; compatibility issues for apps like Yahoo Mail, Google, and Skype Translator; and the ability to use the power button from the Start Menu. The full list of fixes is in Microsoft's blog post on Build 14905.
As with any preview build, there are a number of known issues, including the possibility that Bash may not work after upgrading to this build, though there is a workaround detailed in today's blog post.
Starting today, Windows Insiders who have Delivery Optimization enabled (it's on by default) will be able to get their Insider preview builds, OS updates, and app updates from other PCs on their local networks and the internet. Microsoft initially introduced the Delivery Optimization in the Windows 10 November Update. The main purpose of Delivery Optimization is to make downloads more reliable and rapid.
Microsoft officials have yet to announce specific new features and capabilities that the company plans to deliver in Redstone 2. All we've heard (from sources) so far is Redstone 2, one of two expected Windows 10 Redstone upgrades due in 2017, looks like a Spring deliverable.
Speaking of Windows updates, Microsoft made a number of new fixes and updates available on August 30 to Surface Book and Surface Pro 4 users. Surface Books got several driver updates, as did Surface Pro 4 tablets.
Microsoft also released on August 31 another Cumulative Update (its third so far) for Windows 10 Anniversary Update. That CU, Build 14393.105 includes performance, reliability and specific feature fixes and updates, but no brand-new features.