Resistence
is futile.
You
will be assimilated.
As you have probably read, the Win 10 'proposal' became a bit intrusive on my Win 7 system, while installing updates for Win 10. It screwed up the existing installation, and no restore point was able to fix that. I succumbed and all my data and anything i am and own, now belongs to Microsoft.
I feel sooo fine, it is all very nice here.
There maybe a method to stop this Win 10 installation ..'proposal, but make sure you have a backup (or iso, is the best) or at least some system restore points, before you try any of those tricks.
You have to uninstall some special update (kb numbers provided on the 'net), and then flag it to not appear again, but you also have to remove some bits here and there, otherwise it will just reinstall all after the next syste start, and you have the same problem again.
I did not succeed, but others did