Have you verified what the error message is telling you? - 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.".

Msg 5, Level 16, State 1, Line 0

Named Pipes Provider: Could not open a connection to SQL Server [5]".

Under the SQL Server Properties | Connections | Is "Allow remote connections to this server" checked? If so, what is the "Remote query timeout" set to an extremely low time? Sometimes it is best to set it to zero.

Also, is "Named Pipes" enabled as a connection type?