Question need help !

[herold]

I am developing program for Windows platform. When user transfer some file to specific directory of my server my program should come in to action. In other words I want to develop one program which is in sleep mode. When file is pasted into specific directory from that event the program should be awake and begging to action. When the job is done it will again put it self in sleep mode.Can any one suggest a way to doing it ?

[MiiNiPaa]

Request periodically list of files in said directory. If it changes, start your action.