internet connection problems between XP and Vista

Hi all. My PC is hardwired to BT home hub 2.0 and everything is good. i have a laptop with XP professional and wireless built in. cant figure it out how to get the internet going on my laptop. i did put the network name and key in and skype does connect but only for a minute or two and than goes off again, cant load any pages though. i get message network connected and than disconnected every couple minutes. when my friend came with his laptop and vista in it, internet was going after we put network name and key in.
please help!! cheers.