Our production environment is running sql 2008 r2 rtm in a 3 node cluster (in active, passive, passive mode) - we have tried installing sp1 on it before but due to some legacy installation on the server there is another sql 2008 r2 instance setup that is preventing it from installing. This legacy instance can't be brought back on line or uninstalled (in the usual manner) as the cluster group for it has been removed and the disks that were allocated to it have also been removed and reassigned and are in use elsewhere. I have looked in the registry keys from this article http://support.microsoft.com/kb/953505?wa=wsignin1.0 and can see that the legacy instance is still configured as a clustered instance.
Does anyone have any ideas on how we could progress this by ideally removing the legacy instance ?