SQL Server 2005 Cluster Service pack 4 upgrade failure at remote user account I built SQL Server 2005 ENT Cluster on Windows Server 2008 R2. I need to upgrade it to SQL Server 2005 SP4. However, I get this error at the Remote User Account screen


  Enter the remote user account name and password below.
  User name, Password and domain fields.
  Your account information could not be verified.
  Press Ok to return to Authentication mode screen to determine the reason for failure.
  For setup to verify your credentials the services must be startable, connectable, and you must be a SQL Server Administrator


I am using  an domain account that has access and local admin rights to both servers. The SQL Server and agent run as this domain account and sysadmin .

I got connected using the active node name and also using the virtual name and I get the same error. I also made sure no one is connected to the passive node.

This is my exact error message on the link. But none helped.
http://answers.flyppdevportal.com/categories/sqlserver/sqlsetupandupgrade.aspx?ID=89159030-1f3d-4f13-a693-8122b6bb6aae

The link below from discusses "To work around this problem, use the NetBIOS name of the domain instead of the FQDN" but I do not know where I would be using . 
http://support.microsoft.com/default.aspx?kbid=932870 

Thanks
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.