A while ago I was having a discussion with one of my co-workers regarding the Cluster Service startup account. It was about how someone had changed the Service account password from the Active Directory Users and Groups snap-in and how it had brought down the cluster.
On clusters running on Windows 2000, the password for the service account of the Cluster service had to be changed only after stopping the Cluster Service on all the nodes of that cluster. Starting Windows Server 2003, this has been made really easy. The Cluster service need not be stopped to change the service account password. The best option is that if multiple clusters are using the same Service Account, the password change of that account can be propagated to all those servers with a single command.
The cluster.exe utility is the easiest and safest way to change the password of Cluster Service startup account in Windows Server 2003. Following are some of the examples.
To change password of the service on a single cluster
cluster /cluster:TheClusterName /changepassword:"NewPassword","OldPassword"
To change the password of the service running on multiple clusters
cluster /cluster:TheClusterName1,TheClusterName2 /changepassword:"NewPassword","OldPassword"
The reason for including the password inside double quotes is that, if the password has certain special characters in it, this command will fail. This KB article has more details.