Jesse - Thank you.   I appreciate your help. Dave
I lost ethernet connection between my Inspiron 530s desktop and the cable modem.  I've done my troubleshooting and determined that the cable modem is working correctly and my Internet service is OK - I have a laptop that remains connected to the Internet via WiFi.  I replaced the ethernet cable, so the mechanical connections are OK. The Comcast technician had me check my network adapter files.  I have two: Intel 8256V-2 10/100 Network Connection Microsoft Teredo Tunneling Adapter (which show Error 10) The technician advised that I'm missing a third file; the one that operated the ethernet connection.  He told me to find the missing file at the Dell support site.  When I entered my service tag, the site lists three files under the grouping Modem/Communications: 
How Do I Restore Ethernet Driver(s)