I have a MacBook Pro, running OS 10.5.8. I connected to a Wireless network at my friend's house, entering the router's factory WEP. As I did that I selected "Remember this password" (or whatever that message is next to the tick box). However, my friend had actually changed the WEP to another number. The "factory" WEP allows my computer to connect to the router, but won't let me actually connect onto the Web. With my friend's new WEP all works fine. But now the system remembers the old WEP, how can I make it "forget" that old WEP and ask me for the new WEP again?