title: Updating Android SDK Tools on Visual Studio 2015
body: <p>I'm trying to build an Android app with Xamarin in Visual Studio 2015. But when I opened Main.axml, it showed an error </p>
  
  <blockquote>
    <p>The installed Android SDK is too old, Newer is required. </p>
  </blockquote>
  
  <p>After that, I try to upgrade Android SDK Tools from AVD Manager, However I got the following error message: </p>
  
  <blockquote>
    <p>Downloading Android SDK Tools, revision 24.4.1 URL not found:
    C:\PROGRA~1\Android\ANDROI~1\temp\tools_r24.4.1-windows.zip (Access is
    denied)</p>
  </blockquote>
  
  <p>How do I resolve this problem ? </p>