|Open your router's configuration utility in any web-browser, go into wireless settings and make up your own WPA wireless key using 10 alpha-numeric characters. Then save the new settings before closing the configuration screen.|
Right the key down somewhere safe so you can remember it because you'll need to enter that same key on all your wireless devices, laptop etc.
For most makes of router, you get into its configuration utility by opening any web-browser. Now type 192.168.1.1 into the address-bar, then press <Enter>.