You can have Outlook display a reminder of upcoming appointments, events, or meetings. The reminder displays in a message box and can sound an alarm to alert you. You can use any sound included with Windows or use a sound that you’ve downloaded from the Internet and saved to your hard drive.
Open the appointment, meeting, or event for which you want to set a reminder.
In the Options group on the ribbon’s Appointment tab, choose a reminder time.
Click Save & Close. You will be reminded of the appointment ...