This policy setting allows you to define the number of consecutive scheduled scans that can be missed after which a catch-up scan will be forced. By default, the value of this setting is 2 consecutive scheduled scans. If you enable this setting, a catch-up scan will occur after the specified number consecutive missed scheduled scans. If you disable or do not configure this setting, a catch-up scan will occur after the 2 consecutive missed scheduled scans. Counter Measure: Configure this setting depending on your organization's requirements. Potential Impact: Scanning can impact performance. Fix: (1) GPO: Computer Configuration\Administrative Templates\Windows Components\Windows Defender\Scan\Define the number of days after which a catch-up scan is forced (2) REG: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\Scan!MissedScheduledScanCountBeforeCatchup