Set up wireless

Hello,
ok, there are three laptops in our house currently, one is mine, a toshiba running on vista that i take to school with me. The other two computers are a gateway xp and a hp XP. at home, the gateway XP has internet access to our wireless router (the other computers also used to but don't anymore because of an accident we had when trying to put my laptop onto the system without really knowing what we were doing) I need to know how to get the internet settings from the one XP, to the other XP and Vista, oh yea, and we don't remember the internet key and i can't find it (makes sense you can't find it, it is supposed to be hidden). I know there is a way to do this using a USB drive and we have multiple drives, we just need help connecting. Thank you to anyone who can help.