FWIW: It's not wise to turn off your firewall, since it affords you some protection from ever-present threats (hackers, malware) on the Internet.
As for your connection problems...have you tried the connection troubleshooter?
You might also want to examine Event Viewer for errors that might shed some light.
How To Use Event Viewer - http://www.bleepingcomputer.com/forums/t/40108/how-to-use-event-viewer/
And...you might check with your ISP about possible problems on their end.