Question is about providing auditing (who used the application, when) and securing (who can launch the application - no fine grain control or data security) a desktop application developed you.
What would you prefer?
Have an authentication mechanism built into your application
If using this option, we have to include user and password management, login screen, etc. within the application itself.
Use underlying OS for auditing and authenticating
Here the application needs to be configured after installation such that only users belonging to certain groups can execute the main program or edit the configuration file.