Trying to help a friend troubleshoot. He says it appears his wireless client connects just fine with his router, and gets assigned an IP by the router. But when he attempts any connection to the internet, there's no response. If he is hard-wired to the router, the same computer gets to the internet just fine. So it seems the browser may still be trying to use the wired NIC, which now isn't connected to anything.
How can he check that, or fix it?