When you try to perform one of the following server operating system upgrades, the upgrade is blocked:
Windows Server 2003 to Windows Server 2008 or Windows Server 2008 R2
Windows Server 2008 to Windows Server 2008 R2 or Windows Server 2012
Windows Server 2008 R2 to Windows Server 2012 or Windows Server 2012 R2
Windows Server 2012 to Windows Server 2012 R2
When this problem occurs, the following error message is recorded in the System Compatibility report:
You must make the following changes before upgrading Windows
Uninstall the following Windows components and features: Server Clustering - Please read Microsoft Knowledge Base article: 935197
This behavior occurs because the server is a cluster member. Windows Server 2008, Windows Server 2008 R2, Windows Server 2012, and Windows Server 2012 R2 do not support an upgrade of clustered servers from previous versions. This is because of incompatibilities between the cluster versions.
To work around this behavior, use one of the following methods, as appropriate for your situation.
Method 1: Clean installation
Perform a clean installation of Windows Server 2008 or a later version on the nodes in the cluster.
Install the Failover Clustering feature, create a new cluster, and then reconfigure the cluster settings.
Method 2: In-place migration
To perform in-place migration, go to the following Microsoft website for more information: