Windows 10 / PHP CLI: php.ini file is not loaded from ProgramFiles Folder

I am working with a standard user without administrative rights.

I have installed PHP 7.3.8 manually inside C:\Program Files\PHP on Windows 10.

Afterwards i installed composer 2.0.12. Composer complained, that the openssl extension is not loaded.

I checked everything and finally noticed, that the php.ini is not loaded in CLI mode.

So i added the PHPRC environment variable with the value C:\Program Files\PHP\php.ini and rebooted. Did not work. Checked that with:

php -c "C:\Program Files\PHP\php.ini" --ini
Configuration File (php.ini) Path: C:\WINDOWS
Loaded Configuration File:         (none)
Scan for additional .ini files in: (none)
Additional .ini files parsed:      (none)

Then i tried to add the appropriate windows registry keys like explained here: https://www.php.net/manual/de/configuration.file.php

It also did not help.

So i simply tried to load the file directly by executing:

php -c "C:\Program Files\PHP\php.ini" --ini

It still did not work.

Then i created a hardlink inside C:\Windows\php.ini that points to C:\Program Files\PHP\php.ini

No luck.

Finally i copied the original file C:\Program Files\PHP\php.ini to C:\Windows\php.ini and executed php -c "C:\Windows\php.ini" --ini

And it finally worked:

Configuration File (php.ini) Path: C:\WINDOWS
Loaded Configuration File:         C:\Windows\php.ini
Scan for additional .ini files in: (none)
Additional .ini files parsed:      (none)

Now it became clear, that this is related to access rights. And yes - as an administrator the file did load from inside the Program Files directory.

My Question: As a standard user i have read and execution rights. Why is that not sufficient? What additional rights are required?