Ok so, open up your internet browser and punch in this: 192.168.1.254
Let me know if this works.
Then you would want to access Advanced... if you do not see Port Forwarding, look for Port Forwarding and once you locate that we will proceed. But let me know if that address works or not.
These are the port for PC:
TCP Ports: 3074, 27014-27050
UDP Ports: 3478, 4379-4380, 27000-27031, 27036