Why i can’t use the Wireless network in my range??

I have a laptop and its model is "HP Compaq NC 6000". It does not have WiFi support but is has wireless connectivity.
I get some wireless network signals from my home and I configured them myself. The operating system of the laptop is Windows XP service pack 2.
When I configure the connection, a notification message comes, that I have got connected. But when I try to use the same setting in my browser, the browser can't find any connectivity!!
Can anyone tell me what the probable cause of this problem is? Can you also suggest ways to get connected to the Wireless Network.
Moreover, those servers are not password protected, so there is no basic problems I can find.
Is it a problem with my laptop or the server?? Please someone tell me, what I can do. It's very important, so help as soon as possible.
Thanks.
