You can hardwire it, no problem. Just plug the ethernet cable into a spare port on the router and the laptop and that's more or less it, unless you were using a USB modem or dial-up on the laptop. If you were, delete all connections in Tools > Internet Option> Connections tab, then follow the prompts from the setup button on the same page.
-------------------- OK OK I can't go any faster! aaaaaaaaaaaagh!