title: how to change the .NET version targeted by my mixed-mode assembly
body: <p>I converted a project from VS2008 to VS2010, and now I'm getting at runtime:</p>
  
  <blockquote>
    <p>Unhandled Exception: System.IO.FileLoadException: Mixed mode assembly is built against version 'v2.0.50727' of the runtime and cannot be loaded in the 4.0 runtime without additional configuration information.</p>
  </blockquote>
  
  <p>Googling the error, it seems that you can force compatibility with old assemblies with <code>useLegacyV2RuntimeActivationPolicy</code>, but that's not what I want - I want to build the offending project against the 4.0 runtime.  Apparently the visual studio project conversion wizard didn't do this?</p>
  
  <p>It's a managed C++ project.  How do I change the targeted .NET version?</p>