 <p>This is one way:</p> <pre><code>$metabasePath = "IIS://Localhost/W3SVC" $iisNumber = "12345" $site = new-object System.DirectoryServices.DirectoryEntry("$metabasePath/$iisNumber/root") $site.psbase.Properties["DefaultDoc"].Value = "newdefdoc.htm," + $site.psbase.Properties["DefaultDoc"].Value $site.psbase.CommitChanges() </code></pre> <p>The value returned in <code>$site.psbase.Properties["DefaultDoc"].Value</code> is a comma separated list of documents so you may need to re-jig the order to suit your case. The example above just adds a new default document (<code>newdefdoc.htm</code>) to the top of the list.</p>