The first thing I checked was the seating of the cable. It's in there. I tried another cable, but that didn't help. I tried connecting to the other ports on the router, to no avail. I can move the XP machine's connection to the other ports, and it works fine. Only the Windows 7 machine is having problems.
I uninstalled the adapter through Device Manager and rebooted, but that did not help.
I just finished cycling power to both the router and cable modem, but that did not help.
I did not update the computer's BIOS, if that's what you meant. I did update the router's BIOS, but that was a week or two ago.
My gut tells me I have a bad connector at the back of the PC. I'm going out to buy a PCIe NIC , and shall see if that doesn't fix things.
No one in town sells a NIC. Not Staples, not Best Buy. I'd have to drive an hour to Fry's to get one today, so I ordered this from NewEgg:Intel PWLA8391GT 10/ 100/ 1000Mbps PCI Desktop Adapter PRO/1000 GT - OEM
Hopefully, that will do it.
I did check my BIOS, to see if the network had been disabled some how, but it wasn't. I think this will be the last EVGA motherboard I ever buy. The one this replaced had a faulty BIOS circuit, and kept resetting CMOS whenever the power was turned off. Eight months later, this happens....