Windows Server 2019 Insider Preview Build 17639 (LTSC)
We are pleased to release a new build of the Windows Server vNext Long-Term Servicing Channel (LTSC) release that contains both the Desktop Experience as well as Server Core in all 18 server languages, as well as a new build of the next Windows Server Semi-Annual Channel release. Please also refer to this recent blog announcement about updates to the Windows Server Semi-Annual Channel.
IN-PLACE OS UPGRADE
○ The in-place upgrade allows an administrator to upgrade an existing installation of Windows Server to a newer version, retaining settings and installed features. The LTSC versions and editions of Windows Server that are supported for in-place upgrade are shown in the following table.
CURRENTLY INSTALLED OPERATING SYSTEM AVAILABLE UPGRADE VERSION & EDITION
Windows Server 2016 Standard