Installed FortiClient recently but the challenge in disabling the application/service from running automatically on every start-up annoyed me. Attempt to stop 'FortiClient Service Scheduler' only return 'Parameter is incorrect' error message.
An article on Technet help solve my trouble. To stop FortiClient from starting automatically, try the following: Shut down FortiClient from the system tray. Run net stop fortishield on command prompt. Run msconfig. On msconfig, switch to the Services tab. Clear the FortiClient Service Scheduler check box and click Apply.Run services.msc on command prompt to open up show all available services.Look for FortiClient Service Scheduler. Switch Startup type to Manual.Restart your computer.
FortiClient should not be running automatically the next time round. Hope it helps.