Little or no connectivity. I just replaced my motherboard, RAM, and processor. The computer was

Question

I just replaced my motherboard, RAM, and processor. The computer was tested on the internet at another site and it worked. My internet here works on my laptop so I know it works as well. When I ran ipconfig it gives me the default (auto) addresses for windows XP. The computer is recognizing the newtowork adapter for the motherboard in the hardware tab and when tested it says it works. I have comcast. I have tried everything but I still dont have internet???