I have a networked PC that can do file and printer sharing with the host and other clients but cannot connect to the Internet, apparently because I have a Port 80 situation.

I am a fairly experienced user but have never (even) heard of this problem before. When I check the connectivity of the Internet, I am connected. I even hear pop-ups getting zonked. Apparently my http synchronization is out of whack tho as I can not sign on to any web site.