It sounds like you are connecting to someone else's unsecured wireless network, rather than your one.
Go into the router setup & change your SSID to something recognisable & set it to 'broadcast' (and set a password also) - then when you search for the signal make sure you only connect to the SSID you recognise as definitely yours, enter the password & you should connect..
If that still doesn't work try another channel.
http://kb.netgear.com/app/products/model/a_id/2591