Do you have a "static" IP address set for your network at home?  If so, you can connect to all the wireless networks you want, but you won't be able to connect to their networks, including the Internet, unless your IP configuration just magically happens to match their network. Right-click the network connection in the Notification Area, Open Network and Sharing Center, Change Adapter Settings (left), right-click your wireless connection, Properties, find Internet Protocol Version 4, Properties.  What is selected/showing there?
Hi my Dell d630 with windous XP connecting with any router but connect to internet only with my home router !
Dell D630 Latitude