Make Edition Upgrade in a SQL cluster scenario I have a question in regards to Enterprise Edition to Standard Edition Upgrade. I need to move a SQL Cluster based on couple of SQL Evaluation Enterprise Edition to a licensed Standard Edition. How do I use the new license key?

OS: Windows Server 2012 Std Edition
SQL Server: SQL Server 2012
You aren't able to "downgrade" SQL Server Editions from Enterprise (including Evaluation) to Standard Edition. The Supported Version &amp; Edition Upgrade article details supported upgrade paths.

In the upgrade matrix in the above link, you will notice that the section for Evaluation Edition includes the following note:

 Upgrading from Evaluation Enterprise (a free edition) to any of the 
 paid editions is supported for stand-alone installations, 
 but is not supported for clustered installations.


On a Failover Cluster Instance, in order to change from Evaluation Edition to Standard Edition, you will need to uninstall SQL Server, and re-install using Standard Edition. The same is true in all cases (clustered or standalone) if you are using Enterprise Edition, or Evaluation Edition with any Enterprise-only features.