Taken from this article.

"Game Freezes with Windows 7

If you recently installed Windows 7 and Warcraft III is now freezing while trying to start the game, you may need to patch the game to the latest version. The easiest way to patch is to connect to Battle.net. This can be done by starting the game and clicking on the Battle.net button. If you wish to download the patch manually, please download it from our FTP site:"

I downloaded the patch manually, and when I run it Windows attempts to enter WC3 because that's where the patching action takes place.

Either monkeys writes the articles, or this must be computer generated in some way. What functioning human being could write this? It's funny, I have to admit. But I really want to play Warcraft 3 again, so: Does anyone have an idea of how to fix this? Maybe patch the game from outside the game some how? The game goes black on startup, and after one or two seconds the task bar appears. The intro movie doesn't start, and I suspect that here's where the problem lies.