If the network key is not visible when you go into the router configuration utility, and you don't remember the key, then you will have to reset the router to its default settings (press and hold the reset button on the back of the router for about 10 seconds).   This will remove all security and reset the router's SSID, username, password to the default settings and disable wireless security.  You will then have to reconfigure the router and this time give it an encryption key that you have written down somewhere so you don't forget it again.

 

Steve

Thanks!  I will try that.