John said:
My objective is clearly stated in the original post...
"I want a file manager shortcut opening to drive D. And I don't
want to temporarily reproduce a taskbar icon whenever it's open"
It works properly in Windows prior to version 8.1. They must've
done something to file manager.
I tried a few more experiments.
For example, I tried starting explorer.exe as a separate
process. Task manager tells me a separate process is running,
but the same behavior is exhibited.
Explorer runs the entire desktop.
Explorer owns that folder icon, with the thumbnails
floating above it.
When Explorer is asked to perform as a file manager,
it seems that icon on the task bar inherits the results.
I can find web pages where further hacks are suggested,
changing Runas to _Runas to disable the behavior of always
running Explorer as a single user. The objective there,
is to start an instance of Explorer running as a different
user. My guess is, this is discounted for security reasons.
But I'm not hacking up my registry, any more than it already
is. Trying the Explorer /separate flag and seeing the same
behavior from the taskbar tells me, this is "design intent".
And I'm "swimming against the current". You're welcome to
keep hacking up your Registry if you want. The particular
registry key there has TrustedInstaller as the owner, so
that's the first thing you have to change to try it.
*******
Explorer as another user...
CDCBCFCA-3CDC-436f-A4E2-0E02075250C2
HK_CLASSES_ROOT\AppID\{CDCBCFCA-3CDC-436f-A4E2-0E02075250C2}\RunAs
to
HK_CLASSES_ROOT\AppID\{CDCBCFCA-3CDC-436f-A4E2-0E02075250C2}\_RunAs
Normally that key is set to "interactive user", so a separate
process ends up with the same ownership as the rest of the
desktop. Renaming the key is a dodge to avoid that.
*******
I don't think I can really "break" explorer and destroy the
desktop so Windows 8 no longer boots. But I'm also not heading
in that direction, with any "hack experiments". Too much work
for too little gain.
Paul