title: What's the difference between "aspnet_regiis -ir" and "aspnet_regiis -iru"?
body: <p>The help text of aspnet_regiis utility says the following for "-ir" option:</p>
  
  <pre><code>Install this version of ASP.NET, register only. Do not change any web applications to use this version.
  </code></pre>
  
  <p>And the following for "-iru" option:</p>
  
  <pre><code>Install this version of ASP.NET. If there are any existing applications that uses ASP.NET, it will not change IIS configuration to use this version.
  </code></pre>
  
  <p>It must be my English, but I do not understand what the difference is - both won't change any apps to use this version. And I'm afraid that trying this out myself won't be precise, since I hardly know where to look into...</p>
  
  <p>Does anyone know the difference?</p>