Start Configuration Manager (separate program with that name), go to "SQL server network configuration", choose "Protocols" bellow that - right click TCP/IP and click enable if not enabled already. Right click it again - choose properties this time, choose no for "listen all" unless you are exposing service to other machines, then on next tab choose "Enabled" for addresses you want to listen on (::1 and 127.0.0.1 make sense). Make sure you delete "TCP dynamic ports" and set 1433 for "TCP port" value. Also make sure that your web.config files contain 127.0.0.1 for server address.
