This policy setting allows you to configure the antimalware service to receive notifications to disable individual definitions in response to reports it sends to Microsoft MAPS. Microsoft MAPS uses these notifications to disable definitions that are causing false positive reports. You must have configured your computer to join Microsoft MAPS for this functionality to work.If you enable this setting or do not configure the antimalware service will receive notifications to disable definitions.If you disable this setting the antimalware service will not receive notifications to disable definitions.
Windows Components\Windows Defender\Signature Updates
At least Windows Server 2012 Windows 8 or Windows RT
HKLM\Software\Policies\Microsoft\Windows Defender\Signature Updates!SignatureDisableNotification