title: Is it possible to run a .NET 3.5 DLL in a .NET 4.5 only environment?
body: <p>I have a DLL which has been built targeted for .NET framework 3.5 and used from the COM context. However in Windows 2012 R2 onwards, 3.5 framework is not present; only 4.5 is present. </p>
  
  <p>Is it possible to get it to work without a rebuild on an environment without 3.5 present? I was reading about app.config setting the preferred run-time etc.
  If yes, where should I be placing the config file?</p>
  
  <p>(I saw a few posts regarding scenarios where the executable payload is an application eg. <a href="https://stackoverflow.com/questions/9959743/running-net-3-5-apps-on-net-4-only-systems">Running .NET 3.5 apps on .NET 4 only systems</a>)</p>