When port-forwarding there are two types of IP addresses to worry about: external IP addresses (allocated by your ISP to your router), and internal IP addresses (allocated by your router to your computers).
Your router and your PC should have each have an internal address starting with 192.168, 10 or 172, both of which you'll need to know to be able to forward ports from one to the other. You should be able to open your router's configuration page by typing its IP address in your browser, for example: http://192.168.0.1
Your external IP address (shown in your /whois or by whatismyip.com
) isn't usually
needed when forwarding ports, but take a note of it anyway.