SQL Server 2005 Cluster Service pack 4 upgrade failure at remote user account
I faced the same problem with installing sql server 2005 service pack 3 on windows 2008 R2 cluster. On node1, i brought the sql server group online and pause the Node2 in cluster Manager and then ran the set up on node1. Once setup completed, i resume the node2 and failed over the SQL Server group on node2. Now on Node2, i pause Node1 in cluster manager and run the setup on node2. Once setup was completed, i resume Node1 and rebooted both nodes. I verified the version by failing over the sql server on both nodes.