You can refer to the following steps:
Upgrade from any version of Windows Server that supports WSUS 3.2 to Windows Server 2012 R2 requires that you first uninstall WSUS 3.2.
In Windows Server 2012, upgrading from any version of Windows Server with WSUS 3.2 installed is blocked during the installation process if WSUS 3.2 is detected. In that case, you will be prompted to first uninstall Windows Server Update Services prior to upgrading your server.
However, because of changes in this release of Windows Server and Windows Server 2012 R2, when upgrading from any version of Windows Server and WSUS 3.2, the installation is not blocked. Failure to uninstall WSUS 3.2 prior to performing a Windows Server 2012 R2 upgrade will cause the post installation tasks for WSUS in Windows Server 2012 R2 to fail. In this case, the only known corrective measure is to format the hard drive and reinstall Windows Server.
I hope this information will be helpful to the problems you are having, unfortunately I cannot help you!
Upgrade from any version of Windows Server that supports WSUS 3.2 to Windows Server 2012 R2 requires that you first uninstall WSUS 3.2.
In Windows Server 2012, upgrading from any version of Windows Server with WSUS 3.2 installed is blocked during the installation process if WSUS 3.2 is detected. In that case, you will be prompted to first uninstall Windows Server Update Services prior to upgrading your server.
However, because of changes in this release of Windows Server and Windows Server 2012 R2, when upgrading from any version of Windows Server and WSUS 3.2, the installation is not blocked. Failure to uninstall WSUS 3.2 prior to performing a Windows Server 2012 R2 upgrade will cause the post installation tasks for WSUS in Windows Server 2012 R2 to fail. In this case, the only known corrective measure is to format the hard drive and reinstall Windows Server.
I hope this information will be helpful to the problems you are having, unfortunately I cannot help you!