a windows service that reads from an xml file every minute and displays the update as a pop-up baloon on the desktop whenever new data is added to the config document.

I need to create a windows service just as a task scheduler in vb.net which reads from an xml config file in real time and displays any text in the 'message' tag as a pop-up on the desktop with an ok button. Specifically, I want to create the application to check for any numbers in the message text in 'time' format i.e., 00:00 AM/PM and show the pop-up on the screen 15 minutes before the time mentioned in the text.