Today, Microsoft released the fourth cumulative update to Windows 10 version 2004, this time to PCs in the Windows Insider Slow ring.

Windows 10 version 2004 build 19041.153 (KB4541738) is a cumulative update that includes only quality improvements. And it is, by my count, the fourth time that Microsoft has issued a CU for this pre-release Windows 10 version. Previous CUs were released in mid-January, mid-February, and late February. Because the Insider Fast ring has moved on to Windows 10 version 20H2, the past two CUs have been issued only to the Slow ring.

Key fixes include:

• An issue that might prevent ActiveX content from loading.
• An issue that might cause Microsoft browsers to bypass proxy servers.
• An issue with rendering PeerDist-encoded content in Internet Explorer and Microsoft Edge. [PeerDist is a peer content caching protocol.]
• Security updates to Windows Server, the Microsoft Scripting Engine, Windows App Platform and Frameworks, Windows Graphics, Windows Input and Composition, Windows Media, Windows Silicon Platform, Microsoft Edge, Windows Fundamentals, Windows Authentication, Windows Cryptography, Windows Kernel, Windows Core Networking, Windows Storage and Filesystems, Windows Peripherals, Windows Network Security and Containers, and Windows Update Stack.

Additionally, Microsoft changed how the Linux kernel in Windows Subsystem for Linux 2 (WSL2) is installed and serviced. The firm explained this change in a separate blog post.

“We’re … improving the servicing model of the Linux kernel,” Microsoft’s Craig Loewen explains. “We’ve removed the Linux kernel from the Windows OS image and instead will be delivering it to your machine via Windows Update, the same way that 3rd-party drivers (like graphics, or touchpad drivers) are installed and updated on your machine today. This change will give you more agility and flexibility over Linux kernel updates in WSL2.”