You may have accidentally set up a proxy server, or if you are intentionally using one, its misconfigured. Go to Firefox > Options and go to Advanced > Network > Connection > Settings... There, you can either choose to use no proxy or, if your OS proxy is correctly configured and works (i.e. your IE browser works) choose to use system proxy settings. If you are under a local intranet not managed by yourself, ask your network administration for proxy configuration data, so you can configure Firefox properly. Did this solve your problem? Please report us!