title: Error : Unable to find a version of the runtime to run this application
body: <p>One of the users of my application got the error "Unable to find a version of the runtime to run this application". My application is set to have .NET framework targeted at v3.5. I've asked him to install .NET framework 3.5 but he's still getting the error.</p>
  
  <p>I've tried solutions from several websites, added a config file with the code as follows:</p>
  
  <pre><code>&lt;startup useLegacyV2RuntimeActivationPolicy="true"&gt;
    &lt;supportedRuntime version = "v4.0"/&gt;
    &lt;supportedRuntime version ="v2.0.50727" /&gt;
  &lt;/startup&gt;
  </code></pre>
  
  <p>However the problem didn't seem to go away. The same thing happened on both his computers (Windows XP and Vista). What are other possible causes for this?</p>