TF401145: The selected database {0} is a TFS 2008 database. These databases cannot be upgraded to TFS 2013 directly. You ...

TF401145: The selected database {0} is a TFS 2008 database.  These databases cannot be upgraded to TFS 2013 directly.  You must first upgrade to TFS 2012 and then upgrade again to TFS 2013.  You can download the TFS 2012 RTM .iso from http://go.microsoft.com/fwlink?linkid=255990