If you can't find it in the Netgear then you must know how to get into the settings so go straight to Wireless in the left hand pane then scroll the centre pane to Security and take a note of the key.
If as Netgear says, it is encrypted, all you'll see is asterisks so you need to go back to the left pane and scroll up to ADSL settings, take a note the ISP login and password details so you can then reset the router to factory settings and start again. Make sure you set a strong key - WPA at least and preferably WPA2.
1. Press the reset button on the back until the test light blinks. This takes about 10 seconds. (To avoid accidental resets, the small button is recessed. Use a pen or paperclip to access it.)
2. Release the button.
3. Wait for the router to reboot.
4. Log in with the default password.