You want to receive a notification when your server's processor exceeds 80 percent utilization. You should create a:

A Performance Alert is configured in tools like Performance Monitor to continuously monitor specific performance counters (like processor utilization) and trigger an action, such as sending a notification, when a predefined threshold is exceeded. This directly addresses the requirement of being notified when utilization goes above 80 percent.

A Scheduled task runs a program or script at a specific time or in response to an event, but it does not inherently monitor performance counters and trigger actions based on threshold breaches.

A Performance Log collects performance counter data over time for historical analysis and reporting, but it does not generate real-time notifications or alerts based on thresholds.

A Performance counter represents a specific metric (e.g., '% Processor Time') but is merely the data source; it does not by itself trigger notifications when a threshold is crossed.

A System Event is an entry in an event log that records significant occurrences, which might be generated by an alert, but it is not the mechanism for creating the alert and its notification.