I tried to "edit", but was outside the time window...
Grrr! It is actually much less trivial than I thought... as I tried to use my NSIS installer to set up this test scenario, I created a completely ordinary user ("Fred").
Fred then tried to run my installer, which of course next asked for an admin password... you can guess the rest. Of course the installer was from then on running AS the admin user whose password I had used - NOT as Fred any longer (and of course, NOT using Fred's tree in HKCU).
So even on the latest and greatest Windows (the one having a single-digit name), the access controls seem to be stuck in the Dark Ages... all my NSIS installer is looking for is to be able to DO certain things with an admin's PERMISSION - NOT BE THE *&^*%*&$&^$%& ADMIN!
I know I have asked essentially this question before, but are things really this bad? By its very nature, this entire mechanism of any installer needing admin permission no longer being able to properly install its app into the CORRECT per-user file and registry trees is completely broken.
It is sort of hard to believe that something this broken that sabotages the whole point of wanting to have PER-USER areas of the filesystem (and registry on systems that have one) would ever be shipped. :|
So what am I missing? Or are any solutions to this outside the scope of what NSIS (or any other non-MSI installer?) can do?