Network adapter not reading ethernet

I recently got a new computer, that my brother had built a gave to me. When he first brought it, everything worked fine. I want away for a few days and when i came home it wasnt reading any ethernet cables. As it turns out my router had stoped working. I bought a new one, and now every other computer works, but not mine. I look at the drivers and the Nvida Nforce network controller says its installed and working properly. So out of bordem i grabed and old router that doesnt work anymore, and pluged it in and plugged my computer into it. Now it says there is a cable conected..but not when it is plugged into a working router. I have Vista Home Pre. x64. Any help?

Open a command prompt and type the following without the quotes and paste the results back here, "ipconfig /all". Also open IE, click tools, click Internet Options, click Connections tab and click Lan Settings tab and make sure all check boxes are clear.