(Exported Computer\HKEY_CURRENT_USER limb for each account first, for backup).

I succeeded in enabling/installing the FastReport VCL components by starting RegEdit with my Admin account and exporting the registry limb:

Computer\HKEY_CURRENT_USER\Software\Embarcadero\BDS\23.0

Then, I ran RegEdit with my regular user account then imported the file I exported in the previous step.

More recently, I had similar trouble, though I had not used "Run as administrator" to install FastReports. The install went fine, but the components did not appear, and I was not able to Install the packages within the Delphi IDE. Kept getting "... could not be found" error.

This I remedied by copying the following limb

Computer\HKEY_CURRENT_USER\Software\Embarcadero\BDS\23.0\Environment Variables

from Administrator account registry to regular account registry.