Wirless network connection

I'm having problems connecting my Vista Toshiba A210-19t to any wirelss network except for my home network. This week I am visiting family and i have tried to connect to a couple of unsecure wireless networks but cant get on. I can see them and my itouch connects no problem but my laptop refuses to connect.

I'm guessing there is some setting in Vista i need to change. I have AVG anti virus and windows firewall (although i disabled that and tried to)

Any ideas much appreciated.

Drew.