Active Setup:
It is used when your application requires installation of components such as files or registry keys on a per-user basis, but application has no advertised entry points or other triggers to initiate the installation process.
Run:
The Run key is processed after every logon, either by the Explorer shell, if it is present, or by First Boot Agent (FBA), if a custom shell, Command shell, or Task Manager Shell is used. If FBA processes this key, it does so after every logon, not during first boot as it normally would. Typically, this flag is used to load Systray applications, launch services in executables, hide autostart applications, or hide background processes
Run Once:
The RunOnce key is processed only once, by FBA, after Plug and Play device enumeration and DLL registration processing have completed. The values of this registry key are deleted from the registry after it is processed, so that it will not run again. Typically, this flag is used when a reboot is required, such as for a DLL or OCX registration, or for cleaning up a setup or an uninstall.
