Connecting to an instance of Microsoft SQL Server 2005 database be it the Express, Developer or the Enterprise editions for accessing and updating data or simply for authentication may cause an error while connecting to the server. This is irrespective of whether the connection is from an SQL Server local computer or any other remote computer. It can be caused by SQLCMD utility … [Read more...] about 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.