To get access to your wireless security key you need to enter the routers address into the web browsers address bar and hit enter. The address will be something like 192.168.1.1 or it may be different you can go to the web page of the brand of router you have and get all the info you need including user name and password for the router.
Once you enter the routers address a login window will open for you to enter the user name and password which will let you into the internal settings of the router.
You will need to go to the wireless tab or page and select the wireless security tab or sub menu and that's where you'll find the security key and the option to change it along with the option to chose between WEP,WPA or WPA2 as the key generater with WPA2 being the stronger security.
Save your changes and exit the router, make sure that you write down the security key for safe keeping in case you need it.
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.