Motorola SB5101 Cable Modem, Ethernet Connection Problem


Apr 1, 2010
Hello, I recently got higher internet speed and my ISP told me I must use Ethernet cable to get that speed (as USB cable has a limitation of speed),
so I did.
Unfortunantely, for some reason I can't connect my modem using the Ethernet cable.
my PC just won't recognize it if using the ethernet cable, only when using the usb cable it begins to recognize my modem and I can start with the installation. (beacause if it won't recognize, the installation will tell me to try to get my modem recognized than start installation again...)
I tried to update my ethernet driver on my motherboard (Asus Crosshair IV Formula).
Anny suggestions ?


Oct 17, 2012

Hey there. The problem likely has to do with the software layer you had to install to get usb networking operating with your system and it might be taking precedence over your ethernet controller. Before starting this process make sure you already have the latest driver/firmware for your asus crosshair chipset as well as the usb driver for your modem (in case you have to roll back to the usb connection).

Edit: Before doing any of the below, can you take a look at your 'Start -> Control Panel -> Network Connections', and provide a list of all the adapters listed? Are any of them disabled (an x or an ! mark)?I should have asked this first, apologies.

You need to reboot your machine and check your bios settings during boot. During POST there should be some instructions on the bottom of your screen telling you which button to press to halt the POST process and get into your bios. Often it's DEL, but the information should be available onscreen or in your manual. Once in your BIOS you will need to check out the settings for your motherboard's integrated hardware. I don't know anything about the asus bios, but I'm sure your manual or an online PDF of the manual can point you in the right direction for navigating their bios menu. Once there, make sure your onboard lan/ethernet/nic (whatever verbage is used) is enabled. If not, enable it, reboot and see if your onboard nic is up and running again once you hit windows.

If this did not work:

Now you are in windows, you know your onboard NIC is enabled through the BIOS but you still have no ethernet. Unplug the USB cable running from your cable modem to your computer, and I would recommend removing it from the cable modem itself as well and storing it somewhere if you haven't already. Then go into control panel -> system -> hardware -> Device Manager. Scroll to 'network adapters' and expand so you can see the adapters on your system. You should recognize the name of your cable modem in there, or maybe some oddly named virtual adapters. Delete any virtual adapters and any adapters that directly reference your modem. Now you should simply have your ethernet controller(s) and maybe a 1394 adapter listed. Reboot.

If you still do not have onboard ethernet: install the latest chipset drivers that you downloaded beforehand. Reboot.

If this still did not work: I am out of solutions. Plug your USB modem->PC cable back in and reinstall the software layer and you are at the very least back at square one.