Running Window XP. Why is it that my wifi router's (Apple AirPort) signal, when viewing available wifi networks, appears to be very strong but my computer cannot connect to it but get a message of 'limited or no connectivity'? Same is true when I try to connect to the same router with a Netgear Powerline adapter.

This means you don't get IP address from the AP (access point). This can be, because the ap's owner don't want to make it public and don't setup the router to give IP address to you.

Make sure your security information is correct. The WEP key and type must be exact.

What type of security are you running?

The wireless settings of your router doesn't match with the settings on you computer most important is the wireless security key.. You can check that out on your wireless router...

Hello,
It is you using free wireless?are you know from where and who their admin?

Sometimes,free wireless is like dial-up. For dial-up, it have free ip range and that why by using dial-up, sometimes we see at connection was connected, but it in limited.

For free wireless, it maybe have set to total users that can connect for to maintain it performance. In other view,it like car park. We see that parking,but it was full by other car.

In other question. It is your wireless is secure?Maybe it have encryption or proxy that you must set for to connect to that line. And, if your wireless have provide to register ip,then you must make sure that your ip same and have on that access point.