Windows now has Windows 10 nagware/adware (and how to remove it)
So both my Windows installs (media PC running 8.1 and bootcamp running 7) started display Windows 10 adware, glad to see MS is taking cues from Freemium and malware, including a toolbar icon dedicated just to annoy users.

With a little googling, I discovered that the KB3035583 update is the culprit.
The solution

Step 1:
Go to Control Panels -> Programs and Features -> Installed Updates and search for KB3035583, and remove it. It may take a few moments to find.
Step 2:
When prompted, Reboot.
You’re now Windows 10 spam free. Be aware of the windows update you must first go to installed updates before searching. Otherwise, the search will not find KB3035583.
This winter I’m retiring my HTPC for a Hackintosh. I’d rather venture into the realm of unsupported hardware than continually be fighting MS’s data mining.