The authentication issue is related to the username and password. If you receive that message, it means that the data you're using to log-in expired or disabled. I recommend contacting the website where you acquired the username and password in the first place. Secondly, if there is the possibility, go to Start > Control Panel > Internet Options > Connections > LAN Settings. Make sure that no proxy is set up, or if you have one, check it to be correctly configured.