Your OS has nothing to do with the connection to the router. If the router is configured to allow all clients to connect, then the problem is the Atheros device. Make sure that when you are connected, no other settings are configured for you network adapter (another IP address, dns, gateway, IPV4/IPV6). Go to Control Panel of your computer, then NetWork Connections and Manage Network Adapters when using Windows Vista/7/8 or Network Connections if you use Windows XP. Click properties on the Wireless adapter and set the method of obtaining the IP Address to
Automatic. Then try and connect again.