Help with Mario Kart Wii error code: 86420?

Okay, my dad and stepmom bought me Mario Kart Wii to play with my 6 year old brother, well, when I get back home, I set it all up, we exchange Friend Codes, we notice that when we click on each other's names, it says "Unable to meet up" and below that, it says "Connecting to Nintendo WFC" when we are both already connected.

Now, when one of us goes to the "Create a Room", the other person's Wii makes a sound and says something like "I've created a room!" and when they click "Meet up", not too long after, it says "Communication Error. Please visit support.nintendo.com for more help. Error code: 86420" I go there and what that says makes no sence to me!

"Error Code: 86420

This error occurs when there is a communication problem between players during online gameplay.

Try this:

If your router's security software (firewall) is turned on, it may block communication that is required for online gameplay. To fix this, try disabling the router's firewall*.

Most firewall settings are located under the "Advanced" or "Security" tab.

If the problem still persists with the firewall off, you may need to open ports on your router through the Port Forwarding feature.

Create a manual connection on your Wii and assign a static IP Address.

Open ports 1 through 65535 as both TCP and UDP.

Ensure the ports are forwarded to the same IP Address given to the Wii during the manual setup.

Trouble connecting to a friend?

If the above steps have not resolved the issue and you are trying to connect with specific friends, the problem could potentially be an issue on your friend's network. Your friend will have to perform these troubleshooting steps with their home network.

Using USB Connector or Lan Adapter? Please call 1-800-255-3700 so that we can assist you further.

*While Nintendo provides this information for our consumers' use, it is up to each consumer to determine what security needs they have for their own networks, and to decide how best to configure their network settings to meet those needs."

I don't know how to turn off my router's firewall.

I don't know what to do and I need help with this.

Can someone please hurry and give me an answer to this??

Thanks!

P.S.: I can get on Nintendo WFC and play other people around the world, but when I try to play with my brother, I can't... ):