When Reminder starts (on every Windows boot), it shows itself as a recognizable tray icon (white letter
R in a blue circle) and a Viewer form with events if there are any for that day. If tray icon flashes to
red, it means that you have at least one event with an alarm to come for today, and that you haven't switched off this option in Config. Left mouse clicking on
Reminder's tray icon shows Calendar, and right clicking shows menu with following options:

Calendar shows Calendar form with events
Today shows Viewer form with today's events
Settings show Config form to change settings
Register shows Registration form to enter registration unlock key
Alarms force alarms on/off
Help shows Reminder's help
About shows About form
Exit shuts down Reminder