Check out the "Edit" menu from the menu bar at the top. There are two helpful options listed: "Revert Current Preset to Factory" and "Revert All Presets to Factory". To only restore one of the factory presets, go to the preset number you wish to restore and use the "Revert Current Preset to Factory" option. If you wish to restore all factory presets, use the "Revert All Presets to Factory" option. After using these options you will notice the "Save Preset" button blinking. This indicates that you have to save the preset in order to keep the factory setting in your editor.