title: Visual Studio 2015 not finding Visual studio 2010
body: <p>My visual studio 2015 cannot build 2010 platform toolsets. It says: </p>
  
  <blockquote>
    <p>The build tools for Visual Studio 2010 (v100) cannot be found. To
    build using the Visual Studio 2015 (v140) build tools, either click
    the Project menu or right-click the solution, and then select "Upgrade
    Solution...". Install Visual Studio 2010 (v100) to build using the
    Visual Studio 2010 (v100) build tools.</p>
  </blockquote>
  
  <p>I do not want to upgrade my project or switch the toolset. I have visual studio 2010 installed. It builds the 2012 projects inside visual studio 2015 fine. 2012 also finds the 2010 build tools and builds 2010 projects fine. </p>
  
  <p>Is there a visual studio setting where I can point it to the Visual Studio 2010 directory so that it correctly finds the build tools?</p>
  
  <p>I have tried reinstalling 2010, 2012 and 2015 in that order. </p>
  
  <p>tldr; Visual studio 2015 wont build 2010 projects even though I have visual 2010 installed.</p>