The first thing that comes to mind is to use wget with the builtin Windows Task Scheduler (System Tools->Scheduled Tasks). Of course, since the Task Scheduler is so stupid that the most frequently you can schedule something is once a day, you'd have to set up 92 schedules to make it happen every 20 minutes. I think you can at least do that all as one named task, though. Might be easier to use a better scheduler. A Google for "windows cron" ("cron" is the name of the Unix scheduler) shows pycron, which looks promising.