Search notes:

C:\ProgamData

The directory pointed at with the environment variable %ALLUSERSPROFILE% (typically C:\ProgramData) is used to store application data.
The exact location of this directory is stored in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList in the value ProgramData.
The default seems to be %SystemDrive%\ProgramData (at which also the variable %ProgramData% points).
Some possible subdirectories might include

TODO

The environment variables %ALLUSERSPROFILE% and %PROGRAMDATA% have the same value, at least on Windows 10.

See also

The .NET enumeration System.Environment+SpecialFolder.
C:\Users\All Users is a symlink to C:\ProgramData.

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