If you create a named instance in SQL Server 2005 and you receive the message below you should try the following:

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) (Microsoft SQL Server, Error: -1)

1. Verify that remote connections are enabled.  You can right click on the instance from SSMS and check the connections section to make sure remote connections are enabled or use the surface area configuration tool.

2. If after verifying that remote connections are enabled, you still can not connect, you should enable and start the SQL Server Browser service using the Surface Area Configuration tool.  Once this service starts, you should be able to connect to the named instance(s).