Can you connect to your server from the remote machine from inside your network (behind the router) or outside (in front?) Which did you test from?
For the command line of your server, have you set
+set dedicated 2when you start it?
Are you forwarding port 30720? If not, have you set your server to listen on the port you are forwarding? That would be
+set net_port 666or whichever port you forwarded
This one I don't mean to insult you with (if it does), but post your internal server IP, your external IP, and the port forwarding rule. Quite often I've seen people have a misunderstanding about what gets forwarded where.
Last but not least, post the last few (10-20) lines from the console.
Alright, maybe this should be last but not least, I'm tempted to have a template for these server issues as I no longer respond cause of the boilerplate nature of responses anymore.
edit: Here's a good one that will catch some people. Most versions of windows (if not all) accept incoming on a virtual IP, but will respond from the primary IP. So, if you have multiple IPs set up on an interface, and the server is listening on one of the virtual IPs, there's a good chance that the firewall is blocking outgoing responses since they would be coming from the primary IP, and not the virtual IP that you punched a hole in the firewall for (port forwarding.) This is only an issue if you have and are using virtual IPs. If you don't know, you aren't so don't ask. There are many solutions to this problem, ask around and someone will gladly give you a link :-P