Scheduled scans do not always appear to start when scheduled. This is by design. McAfee has changed the way scheduled scans start to prevent your computer from launching a scan while you are using it, which could cause performance to be slower than desired.When the scheduled time for a scan occurs, McAfee SecurityCenter begins to monitor your computer for activity. If no keyboard or mouse activity occurs for 10 minutes, SecurityCenter then monitors for CPU usage. If CPU usage remains under 10% for 10 seconds, the scheduled scan will begin.