How to: Deploy an Updated Version of an Application
If you use the default update settings for a ClickOnce publication, the application will always try to check the deployment server for updates before launching the application. If there are no updates or if the deployment server is unreachable, the application will just start the last installed version. If the deployment server has an update available, the user will be prompted that an update is available and allow them to accept the update or skip it. If they accept the update, the updated files will be downloaded before launching the application and the new version will launch instead. There are many variations from this behavior possible because of the different update settings in ClickOnce.
In this procedure, you will launch the client application, see that an update is available, and then run that update.
For more information about this procedure, see Automated: Deploy an Updated Version of an Application. For more information about deploying WPF applications with ClickOnce, see Deploying WPF Applications with ClickOnce.