Hello. I recently changed my setup a bit, but I've run into a big problem. My PC that is directly connected to the cable modem won't access the internet. It says there is a network plug unplugged on the bottom, but that is impossible. Not only are all the plugs in, but the second PC is working fine! That's the one I'm on now. How could this one be working, but yet the main one isn't? What could be the problem?