From Softeza Development:
Use Actual Updater to provide the latest version of your application to your customers. Actual Updater is a free tool that allows you to add the update feature into any Windows software. With this feature your users can easily check for updates for your application and install it, if available.
The process is very simple and takes just a few minutes. The program creates three files - two of them you should add into your app's folder and one tiny file you should upload to your server.