Check Card Connections

Check Card Connections
If your onboard LAN icon disappeared from your screen and your network adapter is a separate card or attachment to the computer, check the connection of the adapter. On a desktop computer, a PC card with the LAN port must be seated firmly in the expansion slot on the motherboard. Remove the card and reinsert it to make sure it is seated properly, and perform the same technique with any USB LAN adapter or PCMCIA card that may be connected to the port. Reseating these properly may cause the onboard LAN icon to return to the screen.

Most computers come equipped with an Ethernet port for accessing the Web and the shared resources obtainable through a local area network, or LAN. If your onboard LAN port disappears from your desktop, you can explore several processes to troubleshoot the reason. Be prepared, however, for the chance that you require to replace a defective LAN port on the computer.

Check Cable Connections
On some computers, the onboard LAN disappears when it is not connected or in power-save mode. Check the cable connection to the LAN port to choose if it is firmly inserted. Look for yellow or green lights that indicate a connection. If no lights are present, check the connection to your router or broadband modem to be sure that the cable is firmly inserted and that the router or modem is powered on.

Reboot
Reboot the computer and see if the onboard LAN reappears. Navigate to the device manager in the control panel, find the entry labelled "Network Adapters" and see if your LAN adapter is listed. If the entry is disabled, right-click and enable it. If it's a yellow icon with an exclamation point, reinstall the device driver for the LAN adapter.

Device Drivers
If the onboard LAN disappeared immediately after you installed new hardware or new device drivers, use the "System Restore" utility to restore your computer to the state it was in before you installed the new hardware or device drivers. The computer will very always make a backup of the registry before updating device drivers and you ought to have an entry from before you performed the installation from which you can restore.

Hardware Failure
In case you cannot get the computer to recognize the onboard LAN port, it may have failed. If your computer is still under warranty, you might be able to receive a free replacement. If it was an outside adapter, you can purchase a new adapter to replace it. If the adapter was part of the motherboard and your computer is not under warranty, you may must buy a PC card or USB device to get your LAN access back. Either a wired or wireless adapter, in case you have a wireless network, will return your LAN functionality.