Remote connections error SQL Server 2005

I am getting "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: Named Pipes Provider, error: 40 - Could not open a connection to SQL Server) " when I access my application
But sql server is found to be running
what may be the reason
can any one guide me on thisEverything you could possibly want to know on connectivity issues:

http://blogs.msdn.com/sql_protocols.../22/506607.aspx

Brett
Perfect Computing, Inc