Are you using AVG's firewall & the Windows firewall together? Two software firewalls running at once won't give you better protection - the firewalls will clash with each other & neither one will work properly. Turn off the XP firewall & then make sure your AVG firewall is allowing LW.

Double check all the info that you entered when setting up your static IP. Go back through the steps again & make sure that you write down all the info that you need from the command prompt (when you type in ipconfig/all). Once you're sure that all the info's been entered correctly then move on to the port forwarding. If you did the port forwarding first, don't worry - set up the static IP address & then when you log into your router, you can remove the original port forwarding rules. There should be a box that you can tick, next to the rules, to delete them. Then just do them again

When you set up port forwarding, your starting port & ending port need to be the same number as LW's listening port. And the server IP address will be the static IP address that you set up. Make sure to click Apply at the end.