I don't know offhand what might be causing your problem for sure, but the FAQ in my sig may be some help to you. If you are getting a not responding message on all servers, that sounds like you may be behind a proxy or firewall that is blocking a port you need to have open (599
. If you are on a campus or on any network other than your home network, it is most likely a proxy issue. Not much can be done about that other than to ask the admins of the proxy to add the port to be allowed. Otherwise, if you manage your own router and it is your home connection, maybe try turning off any firewalls and see if that helps.