Event Types

There are five types of events that can be logged. All of these have well-defined common data and can optionally include event-specific data.

The application indicates the event type when it reports an event. Each event must be of a single type. The Event Viewer displays a different icon for each type in the list view of the event log.

The following table describes the five event types used in event logging.

Event type Description
Error An event that indicates a significant problem such as loss of data or loss of functionality. For example, if a service fails to load during startup, an Error event is logged.
Warning An event that is not necessarily significant, but may indicate a possible future problem. For example, when disk space is low, a Warning event is logged. If an application can recover from an event without loss of functionality or data, it can generally classify the event as a Warning event.
Information An event that describes the successful operation of an application, driver, or service. For example, when a network driver loads successfully, it may be appropriate to log an Information event. Note that it is generally inappropriate for a desktop application to log an event each time it starts.
Success Audit An event that records an audited security access attempt that is successful. For example, a user's successful attempt to log on to the system is logged as a Success Audit event.
Failure Audit An event that records an audited security access attempt that fails. For example, if a user tries to access a network drive and fails, the attempt is logged as a Failure Audit event.


Selected activities of users can be tracked by auditing security events and then placing entries in a computer's security log.