How to create a plug-in: 1) Create a new Class Library project that targets .NET 4.0 2) Add a reference to the System.ComponentModel.Composition assembly 3) Add a refernce to the FiveNines.FileWatcherInterfaces assembly 4) Create a class that implements the IFileWatcherPlugin interface 5) Decorate the new class with [Export(typeof(IFileWatcherPlugin))] 6) Build the project and drop the plug-in assembly in the .\Plugins subfolder of the service Note: If your plug-in is compiled with the x86-only flag, you must install the service from the x86 folder (ServiceSetupx86.msi)