您可以从以下链接发出警报.
简单PC闹钟 [ http://channel9.msdn.com/coding4fun/articles/在系统托盘中创建警报时钟 [ Windows任务计划程序 [

You can start with the following links for making alarm.
Simple PC Alarm Clock[^]
http://channel9.msdn.com/coding4fun/articles/Creating-an-Alarm-Clock-in-the-System-Tray[^]

You can read about Windows Task Scheduler[^].

Hope this helps :)