A new test build of Windows 10 Insider Preview build 18343, version 1903 (19H1), is available for Windows Insider members with update priority Early Access.
Windows 10 Insider Preview build 18343.1 (19h1_release) is a new build of Windows 10 (version 1903), which is available to members of the Windows Insider program with the priority of receiving updates Early Access.
This assembly belongs to the development branch 19H1_RELEASE of the next major update Windows 10 19H1, which is expected in spring (March-April) of 2019.
The Microsoft team is approaching the final stage of the 19H1 development cycle, when the main forces of developers will be devoted to correcting known errors and improving the stability of the new version.
New in Windows 10 build 18343 (version 1903)
As usual, the pre-build at this stage of testing does not receive new features, but includes a list of known bugs and fixes.
Windows Sandbox received support for configuration files
In Build 18342, developers announced that the Windows Sandbox now supports configuration files. These files allow users to customize some aspects of the sandbox, such as network support, shared folders, graphics processor virtualization parameters (vGPU).
A full list of improvements, changes and known bugs is available in the official announcement on the Microsoft website.
Installation via Windows Update
Go to Settings > Update and Security and click Check for Updates. To complete the installation, you will need to restart the computer.
Download Windows 10 build 18343 ISO (19H1)
If you want to perform a new installation of Windows 10 Insider 18343, then using the WZT-UUP service, you can download UUP files directly from the official Microsoft servers and automatically create a bootable ISO image using the instructions: