How do I play games on GameSpy?

I have a router and when I try and host a game on GameSpy I get this message:

"GameSpy Arcade has detected that your computer's internal IP address (192.168.1.2) is different than its external IP address (86.***********). This may be caused by firewalls, a NAT proxies, or other unusual network configurations and may prevent you from hosting a game. Please see our Firewall Guide for further information. You can access it by choosing "Help with GameSpy Arcade" from the Help menu."

I can't play games either!!

Please help!

you can't

i dunno coz i never been to gamespy b4...