I lost my internet connection?

I was re-installing Norton anti virus and my internet connection on my other computer disappeared. Under Network Connections only the "Local Area Connection" shows. My other computers are unaffected so I don't think it is related to my router. I don't know how to get my Internet back on that computer. My computer is a Dell Dimension 8200. It doesn't seem to have any other problems. I have had problems with sluggishness since installing Norton and had uninstalled it (including using the Norton removal tool) and had run RegCure. The problem occurred when I tried to re-install Norton from their website.