Windows Program that can track my school schedule?

I am a high school student, and I go to a a high school where we have a "tablet" program--we use Toshiba Portege M780s that can convert into a chunky tablet with a touchscreen. My real question though, is that I would like a piece of software that would alert me when a class is almost over. My schedule is the same day-to-day, and I'd like to be able to see a popup, say in the lower right hand corner that could alert me when I have five minutes left in a class, and all I'd need to do for this to happen is put in the timetable for my schedule. This would be really helpful because I don't remember exact times as to when one class ends and another starts, and the teachers usually go straight to the end without stopping. I also have Ubuntu in another partition, so programs for Linux are fair game as well, but I'd rather have one for Windows. Does anybody know of a program that could do what I want?

Thanks!