Active Setup is a special feature in Windows that allows an application to set up an initial configuration for new users logging on for the first time.
In most cases, this initial configuration includes creating files or registry entries for every user on the computer who logs in for the first time after the application was installed by administrator.
Read more about Active Setup at https://en.wikipedia.org/wiki/Active_Setup, and https://helgeklein.com/blog/active-setup-explained/
Here is an example:
The app is installed by the administrator for All Users on the computer (Per-machine installation). Files are copied to "C:\Program Files\AppName" . And some user-specific files are copied to the current user's AppData folder "C:\Users\%UserName%\AppData\Roaming\AppName". In our case, this files will be created for the administrator only.
Later, when other user logs in, starts the app, it will not find the current user's specific files, because they are not created yet. To create it, you need to activate Active Setup feature in the installer.
Actual Installer supports Active Setup. To enable it, go to Installation / Advanced and select the options "Enable Active Setup" and "Cache Setup File".
NOTE: Active Setup is supported only by the Modern Interface with the following settings (page "General \ Parameters"):
During installation, the setup executable file will be copied to "C:\ProgramData\Package Cache\<GUID>", and a key will be added to the Registry "HKEY_LOCAL_MACHINE\Software\Microsoft\Active Setup\Installed Components\<GUID>". This registry key will contain the app name, version, and a command which perform the user-specific configuration. This command will direct to launch the setup file with a parameter "/AS".
When the setup file is launched with a parameter "/AS", it performs installation only the user-specific data (usually it is copying file to %AppData% folder, and create registry keys in HKEY_CURRENT_USER).