Windows 10: Windows inexplicably not activated and more after recent update

I've had this PC for 2 years, never changed any hardware, but after the recent update it says it’s not activated. Tried re-entering my key at Change Product Key. Thatbriefly confirms it's activated, but the Settings page soon changes to say it can't be activated, AND several hours later the ‘Activate Windows’ watermark returns. The Settings/Activation page says the key has been used on another device, which is not true. Error code is 0xC004C020. Finally, the last 5 numbers of the key shown in Settings are not the same as in my actual key.

PC was purchased new from Dell with Windows 10 Pro preinstalled, but now claims to be WindowsEnterprise. It isn't complaining about that yet, but it's wrong.


Been on 2 long tech support calls with no results. One agent had me try the "default" key; that didn't work either. No other software has been installed or changed for several months, and again,no hardware has been changed, ever. I see posts from a year ago describing the same problem & saying it's an issue with MS's activation servers and is "temporary." Eh??


I know that normally, when Windows isn't activated, certain functions like changing display properties aren't allowed. That doesn't seem to be the case here.

Any ideas? Will the next update reverse this? Will my system collapse in the meantime?

:)

 

Inexplicable restarts

Thanks for your patient help and analysis, zbook. I'll step through some of your suggestions over the next few days - there's a lot to do and some look a bit hairy! That is, for a PC that is working sweetly right now...

Meanwhile, as requested in the BSOD thread (sorry, I misunderstood and posted there by mistake), I've attached both ZIP files.
--------------------
One step I did try right away was to answer your question about whether my BIOS is up-to-date. I had no success at the AMI site but did get some info from this commercial site:





It was one of the '9' (I counted 10) listed here:





Terry, East Grinstead, UK

 

Recent File List

Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file1

Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file2
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file3
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file4
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file5
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file6
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file7
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file8
Remove-ItemProperty -Path "Registry::HKEY_CURRENT_USER\SOFTWARE\Microsoft\Windows\CurrentVersion
\Applets\Paint\Recent File List" -name file9
...

you get the idea. ( too lazy to put it in a for loop and test it.

or just open regedit and remove all the fileX from that key.

 

Child account - Recent Activity & Web Browsing issues not collected

I tried the suggested action, but still not seeing any recent activities listed.