title: error : LNK2019: unresolved external symbol "extern "C"
body: <p>What's wrong with this unresolved externals? I'm trying to implement this into <code>InitInstance</code> of my MFC application. But I'm getting this line error from the debugger.</p>
  
  <pre><code>LNK2019: unresolved external symbol "extern "C" int __stdcall EnumProcesses(unsigned long *,unsigned long,unsigned long *)" (?EnumProcesses@@$$J212YGHPAKK0@Z) referenced in function "public: virtual int __thiscall COkApp::InitInstance(void)" (?InitInstance@COpenEyeProcessApp@@$$FUAEHXZ)
  </code></pre>
  
  <p>Here is the <code>OkApp</code> files :</p>
  
  <p><strong>OkApp.h</strong></p>
  
  <pre><code>//...
  #include &lt;psapi.h&gt;
  //...
  </code></pre>
  
  <p><strong>OkApp.cpp</strong></p>
  
  <pre><code>#include "OkApp.h"
  //...
  BOOL COkApp::InitInstance()
  {
      //...
      if (!EnumProcesses(aProcesses, sizeof(aProcesses), &amp;cbNeeded))
      {
          return 1;
      }
      //...
  }
  </code></pre>
  
  <p>Knowing that my project is coded into <code>Unicode project</code>, how do I to fix this, please?</p>
  
  <p>Any brilliant idea, please?</p>