Working with Reminders
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. Outlook adds a 15-minute reminder automatically when you create appointments or meetings, so you need to use the following process only if you want to add a reminder to an item that doesn’t have one or when you want to change the reminder.
Add or Change a Reminder
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 the Save & Close button. Outlook reminds you of the appointment at the scheduled time.