Disable: 'Check for the latest virus and spyware definitions before running a scheduled scan' This policy setting allows you to manage whether a check for new virus and spyware definitions will occur before running a scan. This setting applies to scheduled scans as well as the command line "mpcmdrun -SigUpdate", but it has no effect on scans initiated manually from the user interface. If you enable this setting, a check for new definitions will occur before running a scan. If you disable this setting or do not configure this setting, the scan will start using the existing definitions. Counter Measure: Configure this setting depending on your organization's requirements. Potential Impact: Scanning can impact performance.

[enable/disable]

(1) GPO: Computer ConfigurationAdministrative TemplatesWindows ComponentsWindows DefenderScanCheck for the latest virus and spyware definitions before running a scheduled scan (2) REG: HKEY_LOCAL_MACHINESoftwarePoliciesMicrosoftWindows DefenderScanCheckForSignaturesBeforeRunningScan