This policy setting allows user to suppress reboot notifications in UI only mode (for cases where UI can't be in lockdown mode). If you enable this setting AM UI won't show reboot notifications. Counter Measure: Configure this setting depending on your organization's requirements. Potential Impact: Users will be able to see reboot notifications in the AM UI. Fix: (1) GPO: Computer Configuration\Administrative Templates\Windows Components\Windows Defender\Client Interface\Suppresses reboot notifications (2) REG: HKEY_LOCAL_MACHINE\Software\Policies\Microsoft\Windows Defender\UX Configuration!SuppressRebootNotification