Computer seems to have forgotten its ethernet adapter

Hello, I am completely new to tom's, and I hope there is someone in the community who can suggest a solution to my problem.

Last week my PC stopped detecting my home network/internet connection. I run XP Professional on one partition, and Win 7 Ultimate on a second. It is about three years old, runs a COre 2 Quad Q9400 processor, 8 GB ram, and I am using an onboard ethernet adapter.

Neither XP or Win 7 can connect to my network which has been running fine for years, both show the little icon in my task-bar with an x over a computer, meaning no connection.

Here is what I know:

The router is working and the other computers on the network are fine, a MacBook Pro, MacBook, IBM Thinkpad, and Toshiba Satelite all are on the wireless end, and my ATT Micro Cell which is connected to the router by ethernet cable works fine.

When I unplug the ethernet cable from the non-functioning PC and plug it into any of the above systems they work fine and connect without a hitch.

There is no Network Hardware, or Network Devices option in the list of hardware in Device Manager.

If I Click "Change adapter settings" in the Network and Sharing Center, I get a blank window.

When the ethernet cable is plugged into the ethernet cable, I get a solid green LED and a solid amber LED next to the port.

ipconfig/all in Command Prompt i get:
Microsoft Windows [Version 6.1.7600]
Copyright (c) 2009 Microsoft Corporation. All rights reserved.

D:\Users\My PC>ipconfig /all

Windows IP Configuration

Host Name . . . . . . . . . . . . : MyPC-PC
Primary Dns Suffix . . . . . . . :
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No

Tunnel adapter Local Area Connection* 9:

Media State . . . . . . . . . . . : Media disconnected
Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
DHCP Enabled. . . . . . . . . . . : No
Autoconfiguration Enabled . . . . : Yes

D:\Users\My PC>

As far as I can tell, both instances of windows have forgotten that they have a network adapter attached. I am at a loss, google cannot help me.
3 answers Last reply
More about computer forgotten ethernet adapter
  1. If the network adapter does not show up in your driver manager than Windows has lost track of the adapter. Reinstalling from the original media may fix it, but it is odd that both installs of Windows would fail at the same time. That suggests a hardware hickup.

    Did you have any power surge or other power event?

    Try the reinstall and see if it works. Or, perhaps an rollback from a restore point.

  2. Ok mike, I was installing the drivers and I got the following error from the installer:

    "The Realtek Network Controller was not found. If Deep Sleep Mode is enabled Please Plug the Cable"

    I have no idea what Deep Sleep Mode is, and so I assume there is no cable to plug in. I am with you, it seems to me that there is a hardware malfunction occurring here, it is strange to me tho, I have never had a network controller fail before.

    Anyone else have any ideas? My motherboard is an MSI P35-Neo-F if that is any help.
  3. Hi rshiery88,

    as I see you have a hardware problem with 3 conditions.

    1. Your Ethernet adaptor is dead. If your board is still in warranty send it back or if not just buy 1 new pci ethernet adaptor.

    2. Your BIOS settings have been set to disable your OnBoard Lan Controller.
    To enable it press Del (Delete) during power on in the first bios screen -> select Intergrated Peripherals press enter -> notice if OnBoard Lan Controller is disabled just press enter and choose Enabled and press enter again. Press one time ESC (Escape) -> Select Save and Exit Setup -> press Y (for Yes) -> Enter again and system sould Boot up and maybe now Ethernet adaptor should appear.

    3. Ethernet controller is enabled But Bios went crazy for some reasonso you have to reseet BIOS. To do so (System has to be shuted down) Plug out the battery from your board for at least 5 mins and after this put it again back and power on your system.

    Note: If you are not familiar with Bios settings don't change something else.
    Remember when taking out the battery to memorize which side of
    the battery was facing to you so you can plug it back correctly.
    After Bios reset Maybe POST* will tell you that "your system has been reset
    Press F1 to continue or F2 to Bla bla" If this is the case than just go in Bios
    again and select save and exit setup.
    *POST = Power on Self Test, it is the very first screen which you see when your
    system is starting up where it tells you most of the times what mobo, cpu, rams,hdd,optical you
    have (if you don't have boot logo enabled)
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