title: Convert c++ project from 4.0 to 3.5 framework
body: <p>I have to change the targeted framework of a c++ project, from 4.0 to 3.5. I have found this question/answer helpful in how to do it: <a href="https://stackoverflow.com/q/2921702/1217150">Change C++/CLI project to another framework than 4.0 with vs2010</a> <br>
  I run into the following problem though: I am getting warnings: </p>
  
  <pre><code> warning MSB3258: The primary reference "path\file.dll" could not be resolved because it has an indirect dependency on the .NET Framework assembly "mscorlib, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089" which has a higher version "4.0.0.0" than the version "2.0.0.0" in the current target framework
  </code></pre>
  
  <p>and the same for <code>System, Version=4.0.0.0</code>, <code>Microsoft.VisualC, Version=10.0.0.0</code>, <code>System.Configuration, Version=4.0.0.0</code>, <code>System.Xml, Version=4.0.0.0</code>, <code>System.Security, Version=4.0.0.0</code>, and <code>System.Data.SqlXml, Version=4.0.0.0</code>. This results in errors in all projects that depend on the file.dll which cannot be found.<br>
  I don't know how to fix this. I have Visual Studio 2008 installed as well - though it doesn't seem to care, and using Platform Toolset v90 makes even the c++ project not build. Please help !</p>