title: Cake build.ps1 fails to install Cake
body: <p>We use the standard build.ps1 PowerShell script supplied from Cakebuild.net</p>
  
  <p>It's worked splendid on both CI and developer machines, but for 1 of our developers we get the following error when launching build.ps1</p>
  
  <pre><code>Unable to find package 'Cake'
  </code></pre>
  
  <p>And then exits, checking tools folder there's no Cake installed.</p>