ADMIN Action
The ADMIN action is a top-level action used to perform administrative installations.
There are no sequence restrictions.
There are no ActionData messages.
The ADMIN action is not called from within the action table sequence, Windows Installer executes this action when MsiInstallProduct is called with the szCommandLine parameter set to "ACTION=ADMIN" or the command line executable Msiexec.exe is called with the '/a' command line switch.