Unable to stop Windows 11 update

I have followed every advice I can find, yet I am still in the same boat as those who have come here to resolve a big issue.  Being an Insider member, Win10Pro system update notified my PC (Intel Z170 Mobo + i7-6900K CPU) that Win11 insider version will be installed on next reboot.  I had already gone and checked my system to ensure my hardware was compatible w/Win11.  A day AFTER/UPON installation of the Insider Win11, the system told me that my hardware became non-qualified (non-compatible) w/Win11.  This is the first time (since days of Win3.x) that I reverted my system back to a previous version because of all sorts of issues I have w/new Win11.

Now, I am being told that the only way to stop the nagging Win11 Install threat is to do a Fresh new Installation of Windows 10 or spend another $1500+ USD to make my hardware compatible w/Win11/

Hey Dufus:  Why do you think we have always stock with WinOS?  Because Microsoft used to respect legacy hardware. Now youa re telling my Skylake desktop is NFG?  I think this is the moment I can assuredly say that Microsoft has become NFG (or the tail that wags the dog).

While I was trying to opt-out of Insider, Microsoft wanted to ask my experience. I went thru the questionnaire to the end and submitted it.  This was the response I received:

Your request failed. Please e-mail The Microsoft Tech Community and provide the date and time you received the error and this Exception ID: 7CC187C8.  Please also provide a summary of the steps you took which led to this error message"