Stop Explorer from opening window to C drive after booting

[videobruce]

I did a long search and I was surprised with the number of hits, including ones that actually want Explorer to open a window at startup. I don't, just the opposite!

Below seems to represent many of the supposed solutions, none that work in my case.
Fix Windows Explorer Window Opening on Startup

I did the basic; looking in the Startup folder,
running MS Config looking under Startup,
I even opened Autoruns v14 from System Internals, but there are so many tabs and entries, it's hard to decipher most of them.

The Registry 'fixes' didn't apply, either because the corrections were already there, or the actual entries weren't, which meant nothing to edit.

I'm running Win 7 Pro x64 if at matters. Never had this issue before. I even ran a couple of virus scans which did find some recent 'nasties' which were removed. Nothing showed in 'Resource Hacker' running that shouldn't be there and no other unusual behavior.