After a lightning storm two days ago, neither of my Dell computers, both of which are connected to the same wired router fed by a Comcast cable modem, would connect to the Internet. With the help of Dell support, I reset my Dimension 4550’s IP address, which allowed me to connect again. However, my Dimension 4600 is showing no IP address at all and there is no light where the Ethernet cable plugs into the NIC on the back of the computer, even when I use the same cable which is working for the 4550. Comcast support says this means my NIC was fried by the lighting. I have a few questions I hope someone can help me with: 

1) Is Comcast correct in saying my NIC is dead or might there be a setting on the computer that needs to be reset?

2) My NIC is the original equipment 'integrated Intel Pro 10/100', which I think means it is connected to the system board and cannot be replaced without replacing the system board. Do I have to replace the entire system board or can I install a PCI NIC in my 4600 (I have an empty PCI slot)? Who makes a good PCI NIC (my 4550 has an Intel, but I don't think they make them anymore)?

3) If the answer to 2 is yes, how will my computer know to use the PCI card instead of the dead integrated one?

4) A Dell telephone salesman mentioned I could use a USB connected NIC. He said it is made by SMC, though I cannot find it on Dell’s site. If a USB NIC would work, how would its performance compare to my original integrated one or to a new PCI NIC? Can you recommend a good USB NIC?

5) I have a surge protector for the computers’ electrical inputs but not for the Ethernet cable. Is there such a thing as an Ethernet surge suppressor? 

Any thoughts would be much appreciated. Thanks a lot.