Do artigo de suporte da Microsoft: Como exibir e gerenciar logs de eventos no Visualizador de Eventos no Windows XP
In Windows XP, an event is any significant occurrence in the system or in a program that requires users to be notified, or an entry added to a log. The Event Log Service records application, security, and system events in Event Viewer. With the event logs in Event Viewer, you can obtain information about your hardware, software, and system components, and monitor security events on a local or remote computer. Event logs can help you identify and diagnose the source of current system problems, or help you predict potential system problems.