After posting the "no internet connection" issue and before walking away from the PC last night, I ran chkdsk for the third time since this all started and attempted to run chkdsk/f, which as in all previous times, indicated it could not as it was locked by a process but was asked if I wanted to run it on startup. Once again I restarted, chkdsk ran on startup but then I just shut down since I was fed up. I found the chkdsk tip, maybe in this community, as advice for someone else who was having connection troubles. This morning after a cold boot, I tried McAfee again and lo and behold, it started to update/install and has been for about 30 minutes with only 50% completed so far. iTunes is also able to access the store w/o error messages.
After 3x, did chkdsk finally fix something? I cynically expect this good feeling to end just as quickly as it started up again.