title: Why app installed using MSI installer would disappear from Windows
body: <p>We made some changes to the installation and updating process of our Windows app recently, and some users are now complaining that Windows sometimes automatically deletes the main application <code>.exe</code> file.    </p>
  
  <p>It usually occurs  after users update app using built-in web update feature. The feature is implemented using <code>.msi</code> built in A<strong>dvanced Installer tool</strong>. </p>
  
  <p>We are struggling to figure out what is causing this, and haven't found a way to consistently reproduce the issue (though we've seen it happen as well).   </p>
  
  <h2>Here's what changed with our installation and web updating process:</h2>
  
  <ul>
  <li><p>The main installer for our application is now a standard <code>.msi</code>, which becomes a part of the <strong>Windows installation system</strong> and is natively manageable by <strong>Group Policy</strong> and other system features, such as <strong>rollback</strong> or versions. In previous versions that did not have this problem, our installer was a <code>.exe</code> built with the <strong>SetupBuilder tool</strong>.</p></li>
  <li><p>We introduced the redesigned web updater feature inside the app (to update to new versions within the app). It uses the same <code>.msi</code> as the main deliverable as for installation. <code>.msi</code> is downloaded from our server in a form of <code>.exe</code> which is then extracts <strong>MSI</strong> and starts it. <strong>MSI</strong> then updates file in our installation. These <code>.exe</code> and <code>.msi</code> is built with <strong>Advanced Installer tool</strong> which provides such a web update feature to developers. In previous versions that did not have this problem, our web update feature was developed with <strong>SetupBuilder tool</strong> which provided a custom web update files -  <code>.exe</code> web updater that downloads a number of web update files containing patch to our app.</p></li>
  </ul>
  
  <p>The goal of a transition to the standard <code>.msi</code> installer was to make it easy for our clients to deploy the app in organizations - say, mass deploy using group policies and other similar tools. </p>
  
  <p>Has anyone else experienced a problem like this? Any ideas on how to troubleshoot and try to reproduce?</p>