What's the Windows equivalent to cron, or for those of you unfamiliar with Unix, how does one schedule a program to run at regular intervals?
With Scheduled Tasks, you can schedule any script, program, or document to run at a time that is most convenient for you. Scheduled Tasks starts every time that you start Windows XP and runs in the background, and it starts each task that you schedule at the time that you specify when you create the task.
Also, you should check out this article from Lifehacker on using Scheduled Tasks. It gives examples for Defragging your computer, restarting your computer, and opening Firefox when at startup with a set of websites
Another idea is to use Cygwin and use VixieCron. You can even install cron as a service so it will run your cronjobs without having Cygwin open. Its perfect for the Unix geek who doesn't have the time or want to learn the Windows way.
Here is a link that should help you get started. Running cygwin cron from windows as a service.