It is strongly recommended that you run a software firewall along with you router. The router will prevent illegal access by hiding all ports however the router will not prevent outgoing traffic (last page visited, keystrokes ect) and thats where the software firewall come in. It will block outgoing traffic at your discretion, as some software you run on your computer loves to broadcast information. I have used Zone Alarm, Black Ice, and I am now using Tiny Firewall. Use the professional edition of Zone Alarm, I don't recommend Black Ice (Does not block outgoing traffic, just intrusions with alerts!) and Tiny is okay.