Specifying Which Runtime Version to Use 

Use the <supportedRuntime> in an application configuration file to target a runtime version. The <requiredRuntime> element was used with .NET Framework version 1.0 and is no longer the preferred method for indicating what version of the runtime an application or component uses. See Targeting a .NET Framework Version for more information.  

See Also

Reference

<requiredRuntime> Element

Concepts

Side-by-Side Execution Overview

Other Resources

Configuring Applications