For SQL 2008:

Take SQL Server (XXX) Resource offline:

>cluster res “SQL Server (XXX)” /OFFLINE

Remove Registry Check:

> cluster res “SQL Network Name (nnnnn)” /removecheck:”SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.XXX\MSSQLServer”

Do whatever you have to configure

Add the Registry Check:

cluster res “SQL Network Name (nnnnn)” /addcheck:”SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL10.XXX\MSSQLServer”

Take the Resources Online:

cluster res “SQL Server (XXX)” /ONLINE

cluster res “SQL Server Agent (XXX)” /ONLINE

“SQl Server (XXX)” is the Name of your SQL Resource in Failover Cluster Management, where XXX is a possible Instancename