Out-of-date drivers and operating systems can cause a variety of issues, and are one of the first things to check when a game is having problems.
How to obtain new CD key files in Warcraft III
Troubleshooting steps for connection problems
What to do if you can't claim a beta key for a Blizzard game.
How to obtain error logs for Blizzard games
Troubleshooting steps for disconnection issues in Warcraft III.
Blizzard's stance on inappropriate behavior in Blizzard games.
Information on what to do when a game update is stuck at 0 B/Ss
Information about this error when login to Classic Warcraft III
Information about error BLZBNTKEY00002034.