ITNinja

VMware Workstation's virtual networking installs two virtual Ethernet interfaces on the host so that your host can access the host- only and NAT virtual networks, which in turn allow your host to access the virtual machines running on those networks and allows those virtual machines to access the host. If you are already connected to a network, you may notice that it takes a little longer to find all the machines on your physical network because the host checks the virtual networks for any virtual machines that may be running.
If your virtual machines are not using NAT or host-only networking or are not running at the moment, you can disable the virtual network adapters to improve your host's networking and browsing capabilities.