You cannot upgrade the operating system of a clustered server from Windows Server 2003 to Windows Server 2008

When you try to upgrade the operating system of a server from Microsoft Windows Server 2003 to Windows Server 2008, the upgrade may be unsuccessful. When this problem occurs, the following error message is recorded in the System Compatibility report:

This behavior occurs because this Windows Server 2003-based server is in a cluster. Windows Server 2008 does not support an upgrade of clustered servers from Windows Server 2003 to Windows Server 2008.

To work around this behavior, use one of the following methods, as appropriate for your situation.

Method 1: Clean install

1. Perform a clean installation of Windows Server 2008 on the nodes in the cluster.
2. Install the Failover Clustering feature, create a new cluster, and then reconfigure the cluster settings.

Method 2: In-place migration

1. Use the Cluster Administrator tool (Cluadmin.exe) to evict the Windows Server 2003-based server from the cluster.
2. Upgrade the operating system to Windows Server 2008.
3. Install the Failover Clustering feature, and then create a new cluster with this node.
4. Use the Migrate a Cluster Wizard to migrate certain settings from a clustered server that is running Windows Server 2003 to a clustered server that is running Windows Server 2008.
5. As soon as you have completed migrating the settings, evict the remaining nodes, perform an upgrade Windows Server 2008 and then join the nodes to the new Windows Server 2008 cluster.

This behavior is by design.

The Windows Server 2008 Help file contains more information about supported paths from Windows Server 2003 to Windows Server 2008 for clustered servers.

For more information about Windows Server 2008, visit the following Microsoft Web site: