trying to run sqlcmd fails, unable to establish connection?

When I try to run sqlcmd (from the cmd prompt) I get the开发者_开发技巧 following error:

HResult 0x2, Level 16, State 1 Named Pipes Provider: Could not open a connection to SQL Server [2]. Sqlcmd: Error: Microsoft SQL Server Native Client 10.0 : A network-related or in stance-specific error has occurred while establishing a connection to SQL Server . Server is not found or not accessible. Check if instance name is correct and i f SQL Server is configured to allow remote connections. For more information see SQL Server Books Online.. Sqlcmd: Error: Microsoft SQL Server Native Client 10.0 : Login timeout expired.

Not sure why this happens? I can connect to the sql server from within my asp.net website (which runs locally, like the database) but sqlcmd can't connect.

If you are not using the default instance, the try then following command:

sqlcmd -S MACHINENAME\INSTANCE_NAME

Notice the capital S. Also notice that I did not give it a user of password, given that default sqlcmd authentication is the windows auth, so I can log in as the current user.
For more information from Microsoft check this out > http://msdn.microsoft.com/en-us/library/ms165702.aspx

Try sqlcmd -S <InstanceName>

• Your command will work only if you have installed the server as default instance.
• Run sp_helpserver to know the instance name.