title: WiX cannot find file when trying to bundle .NET framework dependency
body: <p>I'm getting a strange error when trying to build my Burn bootstrapper with a dependency to the .NET 4 framework. I have downloaded the source of the WiX setup and included the <code>NetFx.wxs</code> in my project and added the PackageGroupRef in the Chain, but I'm getting the following error:</p>
  
  <blockquote>
    <p>error LGHT0103: The system cannot find the file 'dotNetFx40_Full_x86_x64.exe'</p>
  </blockquote>
  
  <p>File <code>Netfx.wxs</code>:</p>
  
  <pre><code>&lt;?xml version="1.0" encoding="utf-8"?&gt;
  &lt;Wix xmlns="http://schemas.microsoft.com/wix/2006/wi" xmlns:util="http://schemas.microsoft.com/wix/UtilExtension"&gt;
      &lt;Fragment&gt;
          &lt;WixVariable Id="WixMbaPrereqPackageId"
                       Value="Netfx4Full" /&gt;
  
          &lt;WixVariable Id="WixMbaPrereqLicenseUrl"
                       Value="NetfxLicense.rtf" /&gt;
  
          &lt;util:RegistrySearch Root="HKLM"
                               Key="SOFTWARE\Microsoft\Net Framework Setup\NDP\v4\Full"
                               Value="Version"
                               Variable="Netfx4FullVersion" /&gt;
  
          &lt;util:RegistrySearch Root="HKLM"
                               Key="SOFTWARE\Microsoft\Net Framework Setup\NDP\v4\Full"
                               Value="Version"
                               Variable="Netfx4x64FullVersion"
                               Win64="yes" /&gt;
  
          &lt;PackageGroup Id="Netfx4Full"&gt;
  
              &lt;ExePackage Id="Netfx4Full"
                          Cache="no"
                          Compressed="no"
                          PerMachine="yes"
                          Permanent="yes"
                          Vital="yes"
                          SourceFile="dotNetFx40_Full_x86_x64.exe"
                          DownloadUrl="http://go.microsoft.com/fwlink/?LinkId=164193"
                          DetectCondition="Netfx4FullVersion AND (NOT VersionNT64 OR Netfx4x64FullVersion)" /&gt;
  
          &lt;/PackageGroup&gt;
      &lt;/Fragment&gt;
  &lt;/Wix&gt;
  </code></pre>
  
  <p>How do I fix this problem?</p>