I’ve removed the uCode from the BIOS and confirmed in UEFI it shows “0” indicating no update.
I’ve deleted mcupdate_GenuineIntel.dll
Full shutdown and power removed.
As soon as windows loads, the microcode is back up to ver 39. (see attached)
Is there a new method that MS is using to update CPU microcode? I haven’t had this issue before.
Edit by Fernando: Thread title shortened
Make a screenshot of regedit with expanded key HKEY_LOCAL_MACHINE\HARDWARE\DESCRIPTION\System\CentralProcessor\0
!Resolved!
Root Cause: A previously installed VMWare Microcode update driver.
"The driver can update the firmware on Intel or AMD CPUs. The driver attempts to update the processor when the driver is started, when the system is booted, or when the system resumed from a low power state (e.g., hibernation)."
Forgot I installed that driver 3 years ago 
Attached is the only way I know of to tell that the VMWare driver is updating the microcode
