Can you describe by brand and model what you have now for your connection?
Does your system have a cable modem or router with both wireless and ethernet wired sockets.
It might be useful to uninstall or remove all the networks stuff, then reconnect just your hardware cable modem or whatever you have. Reboot, then run the install disk for your wired hardware and get it working properly.
Once it is correct, add enable the wireless setup...
This may be far off, until we know what equipment you have and perhaps your provider as well.