Build 10074 was released to Windows Insiders on the "Fast Ring" and "Slow Ring" in late April 2015. It was part of the Windows 10 Technical Preview era, specifically falling under the "Insider Preview" branding. This was the 8th major build released to the public.

: Microsoft has long since replaced these preview builds with stable, retail versions of Windows 10 and, eventually, Windows 11.

A: No. The upgrade path from pre-release to RTM was blocked after July 2015. You would need to clean install final Windows 10.

Windows 10 Build 10074, released in April 2015 as the was a landmark version of the operating system that introduced many of the UI and functional elements we consider standard today. Key Features and Changes in Build 10074