1. Downloading and installing Battle.Lan
First download Battle.Lan here, after downloading extract battle.lan.zip.
copy BattleLANv0.5.exe file in Your Warcraft 3 directory (C:\Program Files\Warcraft III).
2. Using Battle.Lan
Strat BattleLANv0.5.exe before starting Warcraft 3.
1. Launch Battle.LAN on the game host.
2. Enter the IPs of other players. The game host's IP may be omitted.
3. Press 'Add' to add the IP to the receivers list.
4. Click start.
5. Now create your Warcraft game normally. Your friends will see your game in the LAN game and be able to join it.