


NET Framework that the app was built on is not present and a configuration file does not specify a version in a element, the app tries to run on the latest version of the. NET Framework that the app was built on is present on the user's computer, the app runs on that version. If there is no configuration file, but the version of the. NET Framework version listed that is present on the user's computer. The configuration file reads entries in the order they are listed, and uses the first. NET Framework versions, and one of those versions is present on the user's computer, the app runs on that version. If the application configuration file includes entries that specify one or more. NET Framework that an app runs on is determined in the following order: NET Framework and provides an example of how to target version 4 or later versions. This article explains how to enable your desktop app to run on another version of the. However, you cannot change the default activation behavior for Windows Store apps or Windows Phone apps by using an application configuration file.

NET Framework app runs on the version of the CLR that it was built on, but you can change this behavior for desktop apps by using an application configuration file (sometimes referred to as an app.config file). All apps that host the common language runtime (CLR) need to start, or activate, the CLR in order to run managed code.
