This is a relatively rare problem with no known solution. It usually occurs when the game is initially launched, but has also been reported to happen when restoring the game after Alt+tabbing. The only symptom is that the screen freezes and the entire computer becomes unresponsive. The only possible action is to force shut and restart down the computer by holding the power button.

This problem is known to occur on Windows XP and Windows 7, and is suspected to be related to certain graphics cards and/or drivers. Because of the unpredictable nature of this issue, it is recommended to make a habit of saving any work-in-progress and closing other applications prior to launching Warcraft II in order to minimize the risk of data loss.

Generally speaking Warcraft II is a very stable game that runs well on Windows, and the majority of people will be be able to play it without any incident.