No internet

I have latitude E6510, it runs great, it's running windows 7, it's got bluetooth. But it still can't connect to the internet wired nor wireless, all iget when plug the ethernet cable in is the orange or yellow blinking light by the plug and that's it. I've torn it apart and found a WLAN chip and a WWAN chip, the latitude chip is missing, but I don't really need it, and when I got the computer the operating system, which was windows 7, was completely , so had to install my own copy windows 7, and it runs fine other than not having internet which is why I wanted the computer. When I activate the windows network diagnostics it comes up with the ethernet adapter as missing and I found it in the computer itself so I don't know?