Loopback IP and its use

Check whether the network adapter is Working fine:

127.0.0.1 is the loopback address in IP. Loopback is a test mechanism of network adapters. Messages sent to 127.0.0.1 do not get delivered to the network. Instead, the adapter intercepts all loopback messages and returns them to the sending application. IP applications often use this feature to test the behavior of their network interface.

Just ping 127.0.0.1, If you are getting four "Reply" messages then the NIC is working fine. Provided the NIC is not connected using a ethernet cable.