can't connect to internet

i just did a system restore on my computer and have no internet access. it sees the modem, i reinstalled the drivers. the lights on the ethernet port are on, but the computer is not detecting any lan or high speed internet. i have an emachines t3828 with a replaced motherboard. i had this problem before when i installed the motherboard, but i can't for the life of me remember what i did to fix the problem. i use an external modem and a router to connect to the internet. i looked for ethernet drivers for my computer, but can't find any.

 

So there is no NIC card being listed in Networking?

 

no it is not registering that there is one, even though the motherboard has one.