title: Cannot open stdio.h
body: <p>I upgraded Visual Studio from Community 2015 to Community 2017. Now when I build I get error messages saying 'Error (active)    E1696   cannot open source file "stdio.h"' The referenced line looks like this:</p>
  
  <pre><code>#include &lt;stdio.h&gt;
  </code></pre>
  
  <p>If I create a new project, stdio.h is found.</p>
  
  <p>So I looked at the project Configuration Properties->VC++ Directories and I see this:</p>
  
  <pre><code>Include Directories  $(VC_IncludePath);$(WindowsSDK_IncludePath);
  </code></pre>
  
  <p>So it seems that VC_IncludePath needs to be set but I can't find any place to set that. Note that I can't find Macro's and it may be because I'm using the free version of Visual Studio 2017.</p>
  
  <p>Can someone please make a suggestion?   </p>