Microsoft has issued Windows 10 Insider Preview Build 18358 to Insiders on the Fast ring. This one fixes a few more issues and introduces a Windows Defender Application Guard browser extension for businesses using Chrome and Firefox.

“We are releasing Windows 10 Insider Preview Build 18358 (19H1) to Windows Insiders in the Fast ring,” Microsoft’s Dona Sarkar announced last night.

There’s not too much to say here from a fixes/known issues perspective: Microsoft addressed a problem with Game Mode and is still looking for people to test … something … related to gaming via a free version of State of Decay. But nothing major.

Unrelated to the actual build, really, Microsoft is also making browser extensions available for its Windows Defender Application Guard to users of Google Chrome and Mozilla Firefox. This technology is already available for Microsoft Edge as well.

“To extend our container technology to other browsers and provide customers with a comprehensive solution to isolate potential browser-based attacks, we have designed and developed Windows Defender Application Guard extensions for Google Chrome and Mozilla Firefox,” Ms. Sarkar writes. “The extensions for Google Chrome and Mozilla Firefox automatically redirect untrusted navigations to Windows Defender Application Guard for Microsoft Edge.”

To use Windows Defender Application Guard, and thus these extensions, your PC must meet certain requirements, and you must be using Windows 10 Pro 1803 or better. Your PC must also be managed by Microsoft Intune, System Center Configuration Manager, or Active Directory (AD) Group Policy (GP). So, yes, it’s only for business users.