changing computers and routers help!

[#1]

I did some work on friend's laptop yesterday [wanted to see how vista compared with xp] and used it's wifi to connect via my Belkin 54g.  She has since gone to use it at daughter's home who also has a Belkin 54g and now cannot connect via that one as the computer has stored details of mine!  How does she get access again to that one?  Only she cannot keep coming to me now!

[#2]

Under the wireless connections she disconects from your network and then views all wireless networks and connects back to her own.
Its just finding the flipping thing under vista

[#3]

My friend has tried to disconnect  router but it just does not want to recognise her usual one - do you think it is because they are both the same type - Blekin 54g?