The ways to migrate Windows Server 2012 R2 to 2019 is similar to the ways as recommended on this page - migrating Windows Server 2012 to 216. First, you need a reliable Windows PC transfer software that supports you to migrate old Windows Server data, apps, accounts to the new server computer. Next, confirm your goals - to transfer data, apps, accounts between server machines, or to upgrade Windows server to 2019 but keep everything on the computer. Last, take the right solution to migrate Windows Server 2012 R2 to 2019: If you need to migrate everything to a new Server computer, use the PC to PC feature in EaseUS Todo PCTrans Technician and migrate data, apps, accounts to Windows Server 2019 without losing anything. If you need to perform in-place upgrade or clean install Windows Sever 2019 on the old Server 2012 R2 computer, use Image Transfer feature in EaseUS Todo PCTrans to create an image of all important things, in-place upgrade or fresh install new Server, and then recover the image back to the computer.