Microsoft has released the Windows 10 Preview Build 10547 to Windows Insiders, which includes bug fixes and general improvements to the operating system. The full list of changes can be found on the Windows Blog.
The most obvious change comes to Start: Microsoft has added the ability to add a fourth column of tiles to the Start menu. This way, you can have two wide or large sized tiles side by side in a group. You’ll have to go to Settings > Personalization > Start and enable “Show more tiles” for this to take effect. There is now also support for up to 2048 tiles on Start, up from the previous 512.
The new build includes a preview of Object Real Time Communication in Microsoft Edge for developers. The ORTC APIs enable real-time audio and video communications directly inside Microsoft Edge without the need for additional plugins. This is the next step in the collaboration between Microsoft and Skype. Detailed information about the new APIs is available on the Microsoft Edge Dev Blog.
Bug fixes include rooting out many of the causes of the critical error dialog when using Start. In addition, the search function should now work more consistently, the Action Center notification action should no longer light up if there are no new notifications, and several audio issues have been fixed.
There are currently a few known issues relating to the new build. For example, some Windows Store apps may need you to manually check for updates, and you will be seeing a warning message in Windows Update regarding preview builds, but this is safe to ignore for now.
You can join the Windows Insider program by signing up here.