title: Wix: How can I launch a help file after installation? (WIXUI_EXITDIALOGOPTIONALCHECKBOX)
body: <p>I know about WIXUI_EXITDIALOGOPTIONALCHECKBOX and WIXUI_EXITDIALOGOPTIONALCHECKBOXTEXT. </p>
  
  <p>As I understand it, those things can be used to trigger a custom action.<br>
  The examples I've seen run an EXE, or invoke a custom action in code. </p>
  
  <p><strong>How can I run a .CHM file if the checkbox is checked?</strong></p>
  
  <p>If I just specify the chm file  as the FileKey, as below, it does not work. I think that approach works only for EXE files. </p>
  
  <pre><code>    &lt;CustomAction Id="LaunchHelp"
                    FileKey="chmfile"
                    ExeCommand=""
                    Impersonate="yes"
                    Return="ignore"
                    /&gt;
  </code></pre>
  
  <hr>
  
  <p>Thanks to Sascha for the answer...  This worked for me : </p>
  
  <pre><code>&lt;CustomAction Id="LaunchHelp"
                Directory="INSTALLDIR"
                ExeCommand='[WindowsFolder]hh.exe MyHelpFile.chm'
                Execute="immediate"
                Return="asyncNoWait" /&gt;
  </code></pre>