When trying to connect to a data source in SharePoint Designer for BCS you may get this error:
"Cannot connect to the SQL Server database defined in data source connection AdventureWorks"
"A network-related or instance-specific error ocurred while establishing a connection to a SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: Name Pipes Provider, error: 40 - Could not open a connection to SQL Server)"
Check 1: Named Pipes
Ensure "Named Pipes" are "Enable" in SQL Server Configuration Manager in SQL Server Network Configuration | Protocols for MSSQLSERVER.
If it is disabled (as above), right click and click Enable. Then click on "SQL Server Services" in tree and start and stop the "SQL Server (MSSQLSERVER)" Service.
