UNCLE!! I give up 
After spending most of the day chatting with Norton and Comcast, I will get another security program.
Norton says I have a Comcast problem and Comcast says I have a Norton problem.
After installing Norton (and all Live updates) and then rebooting, I try to go to a website and a message says I am not connected to the internet. I check my connection and I am connected. I go to safe mode, and I can get on the web.
I uninstall Norton and then I can once again access the internet using the normal mode.
(Everything we tried today was with McAfee uninstalled.)
I had different problems (browsers crashing) a few weeks ago and posted to Comcast for help, but when I tried to respond to the person helping me I discovered that I was banned from their message board. At that time I restored my new pc to factory settings so I could at least have the free McAfee trial that came with my system. That free trial is almost up, I guess I will go shell out money for something that I am alread paying Comcast for.
The Comcast board told me to remove RapidBoot, but I cannot find it on my system. RapidBoot was also an error today, but Norton didn't address it.