Your network key is set or saved on the router setup page.
There are two ways by which you cna get the key
First you should try this tool.
If you have a computer already conencted to your wireless router,you can download and run the WirelessKeyView tool on your computer from
IT will display your key in plain text in the Key(AscII) column.
IF this doesn't help.
Just open your browser (Internet Explorer or Firefox) on the computer that is wired directly to the router.
Then type in the address bar http://192.168.1.1/or http://192.168.0.1/ the address will depend on the version of your router, or just try both.
Itwill ask you for a username and password, by default the username is XXXXX XXXXX password XXXXX XXXXX
Once you're on the setup page of your router click on the wireless settings on the left hand panel. Then look for the wireless security settings - if the security s set to WEP - Key1 will be the network key or which ever has a tick.
Or if the security is set to WPA the passphrase is your network key. Now that you know the network you can now type it once you are prompted when try to connect to your network.
IF nothing works simply press the reset button on the back of the router for 20 seconds.
Hope this helps.