Improper uninstallation of software (VPN clients or older virtualization tools) can leave the Enumerator in an inconsistent state. It may continue to report "Ghost" adapters—virtual interfaces that are invisible in the GUI but consume resources and cause IP address conflicts. These are often visible using the set devmgr_show_nonpresent_devices=1 command in Device Manager.
A primary use case for the NDIS Virtual Network Adapter Enumerator is VLAN segregation. Consider a server with a single physical NIC (NIC A) connected to a trunk port carrying traffic for VLAN 10 and VLAN 20. ndis virtual network adapter enumerator