I am trying to log on SQL 2005 server sitting on a different location. My security adminstrator has opened all ports but i am still getting this error:

"An error has occurred while establishing a connection to the server. When connecting to SQL Server 2005, this failure may be caused by the fact that under the default settings SQL Server does not allow remote connections. (provider: SQL Network Interfaces, error: 26 - Error Locating Server/Instance Specified) (.Net SqlClient Data Provider)"

Kind regards