title: Getting "Service Unavailable" error when browsing IIS website
body: <p>I have a website in IIS 6.0 using an application pool with a custom service account. When I browse the website, I get an error "service unavailable" and the error in event log says</p>
  
  <blockquote>
    <p>The identity of application pool 'SampleAppPool' is invalid, so the World Wide Web Publishing Service can not create a worker process to serve the application pool. Therefore, the application pool has been disabled.</p>
  </blockquote>
  
  <p>I think the utility "Aspnet_regiis" can be used to grant access to an account to IIS metabase according to <a href="http://msdn.microsoft.com/en-us/library/k6h9cz8h%28VS.90%29.aspx" rel="nofollow">this article</a>, but is that the right way to fix this issue? Because this utility is used for multiple things and may do more than just granting the permissions to the account, or should I just add the account manually to <code>IIS_WPG</code> group?</p>