Simply Remind Me - Free email and text reminder service so you don't forget the important things in life!
Task Scheduler - The Task Scheduler enables you to automatically perform routine tasks on a chosen computer. Task Scheduler does this by monitoring whatever criteria you choose (referred to as triggers) and then executing the tasks when their criteria are met.
FollowUpThen - The simplest way to schedule an email reminder
System Scheduler - System Scheduler for Windows, Free Task Scheduler Software replace Microsoft Windows Task Scheduler
Kana Reminder - Kana Reminder is a program which can be used to set a reminder to be triggered at a specified time.
RoboIntern - An automation and scheduling software with focus on repetitive office tasks.