In the picture above the address bar has http://www.google.com in it. Just replace all of that with the internal IP address of your router. By default the IP address should be set to 192.168.0.1.
Click the Home Network button near the top of the page.
Click the Wireless Settings link near the top of the page.
Click the Submit button.
In the box called Network Name put a name that you make up. You will need to remember this name because it will be used to connect to your wireless network. Do not make it obvious to guess, the network name should be difficult for your neighbors to guess. If you can not think of anything, simply use your first name.
In the box called Wireless Channel, pick a random channel number. Channels make it so that you and your neighbors can use your own wireless networks without interfering with each other. By picking a random channel you reduce the chance of your neighbor using the same channel as you.
Turn on the option called Wireless Network Security.
Put a dot into the Use custom encryption key radio button.
If you are using WPANow you need to make up a passphrase.
Your WPA key can be a plain text, human readable sentence. Make sure it is long, however, because recent hack attempts have exploited short WPA passphrases. Your WPA passphrase should be at least 30 letters long.
Onnce you have made up your passphrase, write it down somewhere. You will need it at each computer that you are going to connect to your network.
If you are using WEPNow you need to make up your network key.
It doesn't matter what this key is, as long as it is random. A network key is a password that is 26 characters long, and made up of only the letters A,B,C,D,E,F and the numbers 0,1,2,3,4,5,6,7,8,9. If you are using 128 bit WEP, then your key must be exactly 26 characters long, and the more random it is, the better it is. Here is an example of a random 128 bit network key:
Onnce you have made up your key, write it down somewhere. You will need it at each computer that you are going to connect to your network.
Now put the key you made up in the box called Key.
If you want to increase your security even more, you can turn your wireless power down. This is a trial and error setting, so you can play with it until you get it just right. Ideally you want to be able to use your network inside your house, but when you go outside you want the signal to be low enough that you can not connect anymore. This ensures that your neighbors can not use your wireless network.
When you're finished, click Save near the bottom of the screen to save your changes.
And that's it! You're done!