Insiders on the Fast Ring can download and install a new Windows 10 Build. Microsoft released Build 16299.15 to the Fast Ring. The new buuild does not include any new features or bug fixes. As the release of the Windows 10 Fall Creators Update on October 17th is coming closer and closer, Microsoft wants to test servicing this build with cumulative updates via Windows Updates. This build is the final Windows 10 Fall Creators Update for Windows Insiders.