You should download HDD Fan Control from this site, see the download link in the top menu bar. You will find “HDD Fan Control.dmg” in the location you downloaded to, normally your Downloads Folder.
HDD Fan Control comes in a Disk Image which you must double click to mount if it has not automatically done so.
HDD Fan Control is a complicated program which runs as a system process to properly control the Fan, hence it must be installed to work. To do this double click on the installer from the mounted disk image. Follow all instructions providing your administrator password when requested.
Once installation has completed HDD Fan Control will be running on your system. If you are running the Demo, you have 1 hour from now to check it does what you need. As HDD Fan Control is a system process it does not have any normal User Interface as such, it has the HDD Fan Control System Preferences Pane to access its Settings, and HDD Fan Control Monitor which communicates with HDD Fan Control and displays Temperature and Fan Speed information in the Status Bar. HDD Fan Control Monitor will also have started and should be visible in the Status Bar.
HDD Fan Control Monitor is also responsible for checking for updates and licensing. HDD Fan Control Monitor can be made to Launch at Login from its menu. You can also Quit HDD Fan Control Monitor if you do not wish to see Temperature and Fan Speed readings on your Status Bar without effecting HDD Fan Control’s operation.