The User Interface tab controls aspects of the way Impact Explorer™ looks.
The "Show large re-assess button" option controls whether a re-assess button appears at the top right of the main window as well as the large continue button. If you find that you often re-assess elements, then this may be useful to you.
The toolbar hiding options allow you to control whether the toolbars are always visible, or whether they are slowly hidden to remove any distractions when you want participants to focus on the main part of the screen. The hiding can be done at all times, or only during the main user activities. When hidden, the toolbars are easily re-displayed just by positioning the mouse over where they should be.
The standard dialog colours option turns off the shaded yellow backgrounds on dialogs. This is designed to be visually appealing (something important with an audience) but you can have standard system colours if you check this option. Most dialogs will change immediately, but some may need the software to restart before this option is effective.
Impact Explorer can be maximized to take over the entire screen display. The fit display to screen on startup option allows you to have it automatically start full screen, saving time at startup.