15 minutes is too early for Outlook 2010 to remind me that I have a meeting at 9:00am. Let me have 10 more minutes of peace! You can change the default amount of time that it will alert you to an appointment.

1. Click the Office button in the upper-left corner.

2. Select Options.

3. Click Calendar.

4. Change the Default reminders to 10 minutes, 5 minutes, or whatever.