Insider Program for Redstone 3 begins with build 16170 for PCs
Microsoft released the first Redstone 3 build to Insider Fast
Microsoft is about to release the official Redstone 2 update to PCs and tablets next week on April 11, but the company already shipped the first test build of Windows 10 from the development branch – Redstone 3.
This first build doesn’t bring new features, but instead focuses on refinements to OneCore in preparation for adding new features in the next builds. So, this early test build from RS3 is only for the die-hard Insiders who are willing to cope with many bugs and issues. The company will also begin shipping Mobile builds in late April, around the official release of Windows 10 Mobile to eligible devices.
From the Windows Blog:
you won’t see many big noticeable changes or new features in new builds just yet. That’s because right now, we’re focused on making some refinements to OneCore and doing some code refactoring and other engineering work that is necessary to make sure OneCore is optimally structured for teams to start checking in code. This also means more bugs and other issues that could be slightly more painful to live with.