1)Open the web browser that you use: Firefox,Google Chrome,IE,or Opera and type in the IP address for your router,and press the Enter key. http://www.routeripaddress.com/< Router ip addresses can be found here
2)A window will open and then type in your routers default username and password,and press the Enter key again http://www.routerpasswords.com/< Router usernames and passwords found here
3)Navigate to the Wireless Security\Network Security Settings Tab and open it to locate or change your WEP or WPA Security Passphrase. Use WPA because it provides better security.
4)Write this Security Passphrase down and put it in a safe place to access when needed.
the computer (unless you actually have it set up as an access point using a wireless card and whatever else you need) is not the access point you are trying to connect to. go into your router settings (usually 192.168.0.1, 192.168.100.1, or 192.168.1.1) go to the wifi tab, and the password should be on there (if it shows up just as dots, there should be a checkbox right next to it to show the password). your wifi password is something you need to remember