LAN does not work

[MrMorgana]

So you are using the same network. Have you tried disabling your firewalls (temporarily) to see, if you can connect then?

[AnthonyCole]

Also make sure you are both running exactly the same version of the game. Maybe one of you is running boosterpack and the other one not (or hasn't even patched the game)?

[AnthonyCole]

You can view the running version on the bottom while in the options menu I think. If you use the wrong shortcut or the autorun you can easily end up starting 2 different version. Always compare the versions shown in the options menu.