Minecraft Forums

I've been trying to LAN connect a HP laptop with no firewall and a HP Computer with firewall. I've tried all of the stuff that every forum I could find recommended, and nothing works. I still get the error "java.net.socketexception: Network is unreachable". This error shows up whether the laptop of the PC is the host. Can anybody help me to fix this? If anybody has a sure-fire way to fix this, I would be eternally grateful. Thanks!