Insert your TFT disc (or RoC if you don't have TFT), Run the game, and Connect to to get automatically updated to the latest version.Run both Downloader_*.exe files and wait until the 1.4GB download completes.Under 'Install / Reinstall the Game', click on the appropriate platform (Windows or MAC).Scroll down to the bottom of the page and click on the newly added Warcraft III: Reign of Chaos button.
Link: /account/management/claim-code.html