There are four elements that need to be installed to enable Natural Search to work correctly with your Help file.
For each help target, Natural Search will generate three files: The Index (.smi), the Noise Word List (.snz), and the Configuration file (.cfg). These files will have the same name as the Help file, and should be installed in the same directory as the .chm or .hlp file.
In addition, the Natural Search Engine needs to be installed. Natural Search provides a setup.exe program, located in the "Redist” folder of the Natural Search installation directory (C:\Program Files\ComponentOne\Natural Search\Redist\). This installs the Natural Search runtime (SmaRTEng.dll) and configures the necessary system information.
Note: The Index (.smi) files for WinHelp and HTML Help 1.x files are not interchangeable and should be installed with their appropriate help target.