10.18 ‘Network error: Connection refused’

This error means that the network connection PuTTY tried to make to your server was rejected by the server. Usually this happens because the server does not provide the service which PuTTY is trying to access.

Check that you are connecting with the correct protocol (SSH, Telnet, etc), and check that the port number is correct. If that fails, consult the administrator of your server.

This error can also be caused by a firewall in between you and the server, which rejects the connection and sends back the same type of error packet as the real server would have sent.