First of all check that you are trying to connect to your router an not a neighbour's by ensuring that your PC is trying to connect to a network with the same SSID as the one that does work.
As to the WPA key. To find it go to your routers home page 192.168.0.1 and then to wireless settings, the WPA key will be there.
As AOL have been so 'helpful' I guess you may choose another ISP when time to renew comes around.
t
September 2008