Windows 10 Insider Preview Build 19041 is the foundation for Windows 10 version 2004 (also known as the 20H1 update). Released initially to the Fast and Slow rings in December 2019, it eventually served as the "RTM" (Release to Manufacturing) base for the May 2020 Update. Key Features and Changes in Build 19041

Added a new option to download a fresh copy of Windows from the cloud when resetting the PC, rather than using local files. Microsoft Learn Official ISO Availability

Developer Updates: This build included a corresponding Windows 10 SDK Preview (Build 19041) with updated API namespaces for UWP applications.  System Improvements and Fixes 

4. Offline Air-Gapped Systems

In secure environments where internet access is forbidden, you cannot download the latest ISO from Microsoft. If an organization keeps an internal repository of ISOs, Build 19041 might be the last officially verified version for a specific hardware stack.