Windows 10 version 2004 isn’t yet available to the public, but Microsoft has issued a cumulative update to the Slow ring of the Insider Preview program. Build 19041.84 (KB4539080) is a cumulative update, meaning that it includes only “quality updates,” or security and bug fixes.
Security updates. Microsoft Edge, Internet Explorer, the Windows App Platform and Frameworks, the Microsoft Graphics Component, Windows Input and Composition, Windows Media, Windows Shell, the Microsoft Scripting Engine, Windows Fundamentals, Windows Management, Windows Virtualization, Windows Peripherals, Windows Network Security and Containers, Windows Storage and Filesystems, and Windows Server have all received security updates.
Bug fixes. Microsoft says it has fixed an issue “where in certain cases, after Windows runs a scheduled task during a maintenance window, a PC may get into an unbootable state after installing Build 19041.21 (KB4535550).”
Curiously, there are still some known issues worth mentioning—like an incompatibility between Narrator, NVDA hardware, and the new Microsoft Edge—but then that’s why Microsoft is using this weird new release cycle: It is updating each release for a few months between the time of its completion and when it is released to the public. Based on the version number, we expect Windows 10 version 2004 to ship publicly in March or April.