Minecraft LAN not functioning?

Me and another person have been attempting to play a minecraft game together for sometime. We can't get LAN to work, even with Hamatchi. YES we're on the same router. A list of troubleshooting steps would be helpfull.

The server PC needs to have the appropriate ports open in its firewall. A quick search indicates that port TCP 25565 is the default.

NB: You don't need hamachi if the clients and server are already on the same network.