web and win form

Question

I work with web form, I did application in aspx that send messages / missions in the network with all the workers. now I want to add small win application that runing on the computers and when the worker get a message its add a small form from the notifyIcon. and write: you have a new message from "XXX" subject : "TTT" doubleclick open the explorer in the correct message. I have no idea where to start, timer? web service? any idea? thanks!