If you notice that your PC is no longer displaying a valid network connection then there are a few steps you can take that may fix your issue.
1) Check network cables in the back of the phone are connected securely.
2) If they are then make sure the network cable in the back of the PC is connected.
3) If the issue still persists then restart and see if it picks up network again.
If this still doesnt get the network on then raise an incident through the portal.