Nik collection n'est pas installé sur votre ordinateur

It’s a great news that Nik 4 is finally available from PhotoLab UI.
To be honest, it’s the first time that we receive a feedback about permissions mismatch in the registry leading to this issue so I would say that is specific to your computer.
Did you use any third-party Windows utility to manage your registry/installed programs or to harden your system?

For the ACL command you posted, I have a different Owner (System instead of Administrators) and I have more Access groups (+ Users and +SYSTEM). It makes me think that an utility has changed the permissions in the registry.

Best regards

No, I did not use any third-party Windows utility to manage the registry/installed programs.
It’s the first time I face this type of issue.
Thats why I removed and I reinstalled the Nik Collection 4; in fact to state that there was a permission issue with HKEY_LOCAL_MACHINE\Software\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall\Nik Collection
I had to manage the Regedit Autorisations sub-menu to solve the issue.

I recommend running the sfc and (if necessary) dism commands to scan for and fix corruptions in Windows. For example:

Top 5 Ways to Fix Corrupt Registry in Windows 10 (4winkey.com)