As you don't provide a link to previous posts can't follow old thread, but if you have a new router then you must add details of your isp into the router so it can connect. Follow router set up instructions for this. Was there a software installation dissk that came with it? If you old router is disconnected, as it should be, then your pc won't be trying to connect through it.
Router should have a web page interface usually accessed by entering http//192.168.0.1 into IE address bar. Via this you can manually enter the ISP details.