Hi, why in my Server 2008 R2 standard have a features Fail over cluster,

It is included in the release two?

I have the same error when i try to create a cluster "The [computer_name] does not have failover clustering feature installed. Use server manager to install the feature on this computer"

With the release of Windows Server 2012, Microsoft started including the Failover Cluster feature in Standard Edition.  Prior to 2012, Enterprise or Datacenter Editions were needed for Failover Clustering.