How will you find that the NIC card is working or not ?

Option1

Go to Device Manager, network adapters, Network Adapter / Ethernet card and right click and select the properties, in General tab under the device status see the message, if its working properly it will show the following status: 

 This device is working properly.

Option2

In CMD, type IPCONFIG /all

1.To test your NIC card Ping the following IP.0.0.1(loopback ip) it is the internal layer3 IP address built in to your NIC card. You can ping this with the machine not connected to anything.(Quick check).

2.Otherwise in device manager( go to command prompt and use devmgmt.msc), expand the section for network adapters then right-click on your network adapter, select to display the properties and check the device status.

Follow these steps to check on the NIC hardware:

1. Open the Control Panel.

2. Open the Device Manager.

   • In Windows 7, choose Hardware and Sound, and then choose the Device Manager link beneath the Devices and Printers heading.

   • In Windows Vista, choose Hardware and Sound, and then choose Device Manager.

   You need to type the administrator password or click the Continue button to proceed in Windows Vista.

3. Expand the Network Adapters item to view all network adapters installed on your PC.

   You most likely have only one.

4. Double-click the Network Adapter entry to display your PC’s network adapter’s Properties dialog box.

   The General tab in the Properties dialog box lists the device status. Any problems detected by Windows appear in that message box. Otherwise, the message reads This device is working properly.

5. Click the Resources tab in the Properties dialog box.

6. Check the Conflicting Device list.

   You should see no conflicts listed. If not, the source of the conflicts must be resolved. Generally, it would mean removing whatever other device is conflicting with the NIC or reconfiguring the device.

7. Click OK to close the Properties dialog box.

8. Close the Device Manager window as well as the Control Panel.

Use loopback ping 127.0.0.1 this ensures the NIC card is Working.

PING 127.0.0.1 if you are getting the replies using the cmd then it is working 

At first check either the NIC driver is installed or not in device management, if it is not installed we should have to install the driver software and then should have to check connecting to the network and confirm is it connecting/ transferring information from the network source.

Go to command prompt and try to ping an IP 127.0.0.1 If its replayed without any packets its mean the NIC card is working properly 

when there is no network connectivity on the pc 

ping to 127.0.0.1 it show the result and browser to device manger then status of NIC from list of hardware,

Send ping to modem/router/next pc from the command prompt & look for the reply.

start /run / cmd

type "ping 192.168.1.2" (local network)

or

type "ping 8.8.8.8" (google dns)

If u r getting reply, then it is working fine. If there is no reply, then check the ethernet driver at system properties / device manager / ethernet controller. Also check for cable connectivity to the switch / router.