Hello
Yes, it is possible to migrate the WSUS database from a Windows Internal Database (WID) on a Windows Server 2012 R2 to a new server running Windows Server 2019. Here are the steps you can follow to migrate the WSUS database from WID to a new server:
1.Stop the IIS and WSUS services on the WSUS server. From PowerShell (elevated), run: Stop-Service IISADMIN and Stop-Service WsusService.
2.Detach SUSDB from the Windows Internal Database. You can do this using SQL Management Studio by right-clicking SUSDB -> Tasks -> click Detach. Check “Drop Existing Connections” and click OK (optional, if active connections exist).
3.Copy the SUSDB files to the new server. Copy SUSDB.mdf and SUSDB_log.ldf from the WID Data Folder (%SystemDrive%\Windows\WID\Data) to the new server.
4.Attach SUSDB to the new server. In SQL Server Management Studio on the new server, under the Instance node, right-click Databases, and then click Attach. In the Attach Databases box, under Databases to attach, click the Add button and locate the SUSDB.mdf file (copied from the WID Folder), and then click OK.
After completing these steps, you should be able to connect to the migrated WSUS database on your new server running Windows Server 2019.