I have cable modem access to the Internet. Suddenly I was denied access to any website. The Cox cable technician traced the problem to my firewall. When I disable it everything works fine. I am using Trend Micro PC-cillin Internet Security 2005. I did not change any setting when this happened. I tried to change my firewall security from high to medium, but this didn't help. I have windows XP Professional, and run with XP firewall disabled.