Yes, you can do an in-place upgrade from 2012 R2 to 2019. Here is how to do it.
To perform the upgrade
Make sure the BuildLabEx value says you're running Windows Server 2012 R2.
Locate the Windows Server 2019 Setup media, and then select setup.exe.
Select Yes to start the setup process.
For internet-connected devices, select the Download updates, drivers and optional features (recommended) option, and then select Next.
Setup checks your device configuration, you must wait for it to finish, and then select Next.
Depending on the distribution channel that you received Windows Server media from (Retail, Volume License, OEM, ODM, etc.) and the license for the server, you may be prompted to enter a licensing key to continue.
Select the Windows Server 2019 edition you want to install, and then select Next.
Select Accept to accept the terms of your licensing agreement, based on your distribution channel (such as Retail, Volume License, OEM, ODM, and so on).
Setup will recommend that you remove Microsoft Endpoint Protection using Add/Remove programs.
This feature isn't compatible with Windows Server 2019.
Select Keep personal files and apps to choose to do an in-place upgrade, and then select Next.
After Setup analyzes your device, it will prompt you to proceed with your upgrade by selecting Install.
The in-place upgrade starts, showing you the Upgrading Windows screen with its progress. After the upgrade finishes, your server will restart.
Hope this helps!
Regards.
Aby
