title: Target a specific .NET framework
body: <p>As we know, at Visual Studio for C# project, we could specify what .NET framework we want to target. Here is the app.config file I got when it is target .NET 4.0:</p>
  
  <pre><code>&lt;configuration&gt;&lt;startup&gt;&lt;supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0"/&gt;&lt;/startup&gt;&lt;/configuration&gt;
  </code></pre>
  
  <p>So there is sku attribute there. Does this mean that my code won't work on machine where .NET 4.0 is NOT installed while .NET 4.5 is installed. I found out that it is confusing from MSDN and I want to get some clarification on this. If so, I would say that is rather bad design. What if I want my code to run on any .NET version of .NET 4.0 and above such as .NET 4.5? I could not distribute different app.config for different env.</p>