iMac wireless internet lost

[rebeccam]

Hello,
My iMac (intel core duo, running 10.4.11, about 2 years old) has never had any problems connecting to my wifi box via airport - then suddenly it won't work any more (nothing changed - just one day to another). Airport status is connected to my wifi network, but there is no internet connection. The connection via ethernet cable works fine, so it can't be an ISP or router problem (in any case my Mac laptop has no trouble picking up the wifi), and when I search other neighbour networks via Airport, it gets me to their ISP login page, so I doubt its a hardware problem.

Called apple who said I'd probably need to reset the wifi / airport system configuration and create a new location - but for her to talk me through it (with no guarantee of a fix) would cost me. So I tried to do what I can (deleting certain system files etc) but I don't really know what I'm doing, and nothing has worked so far.

Can anyone help?

 

[eric2006]

What is your network configuration? If you could provide details about the wireless setup it may help. You should try to restart the router and verify the settings in case, but since the laptop works this may not help.
As far as resetting the airport, you should try to create a new location first, this should get you back to the default settings;
http://support.apple.com/kb/HT2712
It sounds like the wireless is working but the network settings are such that something isn't quite right for accessing the internet (no IP given?). You can make sure that your wireless is functioning if you can access the control panel of the wireless router.