You should NOT disable your desktop firewall. The problem is, routers assume everything coming from the "Trusted Zone" (your side of the router) is... "trusted" or safe. They also assume you know where you are going when you surf. And understand NAT's primary purpose is to allow multiple computers to share the same network connection. This does help hide your computer's true IP from wizkids and wannabe hackers, but offers little resistance to an experienced badguy. It is great you have a router, and I think every broadband user should, even with only one computer, but you still need a software based firewall on your computer. This helps ensure that should something get buy, or a user lets something by, and it attempts to "phone home" with your personal information or other payload, the computer based firewall will yell at you for permission.