For some reason, the Ethernet controller on my Mom's computer is not visible to the operating system at all. It's been like that for 3 years, and she's been using WiFi as a substitute. The warranty on the machine is already expired and she should've RMAed it then, but Moms. The problem is especially aggravating because a special Ethernet cable that's 100 miles long was purchased and installed so that she could connect directly to the router. There are no references to the Ethernet controller in Device Manager at all, and attempting to install the driver using the automated installation program from the Dell website results in an error saying that the controller was not detected, and the installer undos its work. I also tried the Add Legacy Hardware option in Device Manager to install the driver by clicking the Have Disk button and selecting the INF included with the installer, but nothing shows up in the window where you select the driver to install so I couldn't click Next. Someone suggested to unplug the computer, remove the CMOS battery, hold the power button, and whatnot, but that did nothing. Someone else suggested to disable the on-board Ethernet controller in the BIOS, boot, then go back to the BIOS, enable it, and boot again, but that still did not make a difference. It's not a big issue since the WiFi speed is still decent, but it would be best if it worked. The computer was never upgraded and still has the stock operating system.
Thank you for your question.
Due to the troubleshooting steps you have performed so far, it is my strong assumption that the network card's firmware is corrupt in such a way that the chipset can't even seen it. Your issue likely requires motherboard replacement.
Few options for you:
1. Send me a friend request and once I accept, I will PM you and you can reply with your service tag and I'll see about getting a motherboard quote for you.
2. I can quote you one of our PCI network cards.
3. Run to the local electronics store and grab yourself a PCI network card.
I've had to do option 3 before my self after a lightning strike. Way cheaper and way quicker than a motherboard replacement.
Please reply back with any further feedback or questions on this.
Justin C Dell Technical Support | Project Sputnik
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