The Do not allow manual configuration of target portals machine setting should be configured correctly. If enabled then new target portals may not be added and thus new targets discovered on those portals; existing target portals may not be removed. If disabled then new target portals may be added and thus new targets discovered on those portals; existing target portals may be removed. Fix: (1) GPO: Computer Configuration\Administrative Templates\System\iSCSI\iSCSI Target Discovery\Do not allow manual configuration of target portals (2) KEY: HKLM\Software\Policies\Microsoft\Windows\iSCSI\ConfigureTargetPortals