Windows deactivated (and edition changed!) after recent update

Had this PC 2 years. After the recent Windows Update it says it's not activated. ADT and LicensingDiag outputs are attached. Version 1809, OS Build 17763.864. Details below; some differ from the more usual scenario for these questions (of which I've read several dozen):

• Never changed any hardware. Windows has never been reinstalled or reset.
• PC was purchased with Win10 preinstalled, so not an upgrade.
• Purchased from Dell, so presumably genuine. Never had activation complaints til now.
• Re-entering my key briefly confirms it's activated w/digital license, but Settings quickly reverts to saying it can't be activated, claiming the key has been used on another device (not true). Gives error code 0xC004C020. Troubleshooter there is no help.
• Machine has always been Windows Pro, but now says it's Windows Enterprise -- ehh?? Running winver confirms this, and also says it's registered to "user name" instead of to me, as it used to.
• The last 5 numbers of the key shown in Settings are not the last 5 of my key.
• Entering the Googleable "default" key fails similarly.
• In Services, Software Protection weirdly showed as "stopped" (I'm sure I'd never stopped it). I restarted it; no change.

Made 2 exhausting support calls to Microsoft, both useless. Got escalated to Level 2 but those guys apparently never answer their phones. Any clues much appreciated.

BTW am considering doing a Restore and deferring updates til next month. Bad idea? I use this PC for professional presentations so having that Activate Windows watermark is gonna look awkward.

Thanks in advance.
Mark

For some reason its turned into enterprise which doesnt activate from MS but a local server for VL. The quickest option is to get the lates iso from MS free and do a clean install of pro

mark99k said:

Machine has always been Windows Pro, but now says it's Windows Enterprise -- ehh??

You could try downgrading Enterprise to Pro....

Downgrade Windows 10 Enterprise to Windows 10 Pro

...try using your Pro key first. If that doesn't work, try the generic key for Pro: VK7JG-NPHTM-C97JM-9MPGT-3V66T

As this machine should already have a digital license for Pro it should activate, even if you used the generic key.

Oh lord, I can't even fathom the task of reinstalling all my programs, settings, etc. What would be your second choice method, if any? And what, if any, are the disadvantages of just leaving it like this?

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Thanks, this sounds promising. To leave town today but will try this when I get back

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Not a gamer (am in my 60s) and have never had any games installed. My activity is all very ordinary -- Word, Excel, YouTube, emails -- so I can't imagine what I've done to provoke Windows into behaving strangely

Jacee said:

Please see if this helps: Fix: Activation Error 0xC004F025 on Windows 10 PC - Howtoedge

Hi Jacee - This didn't help, but it did change the error code (to the one in the link) and slightly change the error message. Is that good?

What would be the disadvantage, if any, of leaving the PC in its unactivated state? Reinstalling would trash so much of what I need that I really just can't consider it.

Superfly said:

Did you follow @Bree's advice on downgrading? It will retain all apps and settings.

I did. I wasn't optimistic because it's basically what I'd tried several times at first: entering my key (or the default key) in Settings/Activation. And this most recent time it actually seemed to stick! I kept checking it at intervals, for about 3 hours, and it still said it was activated (and Pro). (Previous attempts had reverted to Enterprise and the can't-activate message within a minute or so.)

So I was about to post a big ecstatic thank-you and mark it solved, but when I checked it again just now, it's back to the error. The only difference is that now, when the error appears (very quickly), it invites me to "try activating again later" or go to the Store to buy genuine Windows (again!?).

I'm really at the end of my rope. What's the downside of leaving it this way? Do things stop working? Nothing seems to be protesting yet. Thanks for all your attention.