On March 24, Microsoft released a new preview build for the Dev channel, Windows 10 Insider Preview Build 21343, to testers of the Insider program. In this build, the underlying sandbox technology has changed and the Explorer icon has been updated.
Provided by: Microsoft Both “Windows Sandbox” and “Microsoft Defender Application Guard” use the container technology built into Windows 10. Previously, the runtime of this container matched the runtime of the host OS. However, Microsoft stopped this from this build and changed to a lightweight line time optimized for container scenarios. This is expected to improve performance without affecting compatibility, he said. Build 21343 has many other fixes and updates, but there are still known issues.