Use this button in the Marquee Control Panel to Launch Marquee if it is not running, or bring the main window to the front if it is. If the Control Panel is visible, pressing the [Spacebar] is equivalent to pressing this button.

If you press this button while Marquee is not already running, Marquee will start with a new show file.
Check the Up Time to see how long or if Marquee is running.
If you see this icon:
the Control Panel is installing new software and you cannot launch Marquee at this time.
Back to Marquee Control Panel