Shortly after 3 am today, I noticed my Win 7 SP1 computer was about to automatically restart in order to complete installing updates. Before I could abort this, the computer restarted. And I immediately noticed that wretched Icon to "Get Windows 10" in my notification tray, with no way to remove or disable it.
When I checked my view updates history in Control Panel>Windows update, I saw that no less than 39 "Recommended" updates had been installed on May 31 - some issued as far back as 2012. Not one of them applied to issues on my system (the ones fixing problems with Lithuanian and Russian currency spring to mind as examples). In short, they all looked like updates I had hidden.
I checked my Windows Update settings, and Automatic Updates was still disabled. I went to Windows Update, and my "Hidden Updates" folder was empty. Well, at least I knew the what and where, if not the how and why, of what had happened.
Well, it was easy enough to uninstall the update that put the "Get Windows 10" icon in my tray - I just uninstalled the KB3035583 update from Control Panel in the usual way. Only took 3-4 minutes, including a system restart. Great - one uninstalled useless update down, only 36 to go. That should only take 2-3 hours.
But KB2600217 and KB2901983 were .NET Framework updates I had hidden back in 2015. And when I check Windows Update, it is now offering me no less than 12 Important .NET security updates that have been issued since 2014, totalling some 50 Mb. I suppose those "hidden" .NETs wiped them out. So I tried installing the oldest one offered. That whole process only took 7 minutes, including a reboot. So I threw all .NET caution to the wind, and installed the 11 remaining at one go. All installed without glitches, and WU isn't offering me any more updates now.
As for those 36 "hidden" updates now installed, I think I'll ignore them for now. With luck, they might not cause any grief. And at least I won't have to worry about all my Lithuanian and Russian investments ...