Index: src/wp-admin/css/install.css
===================================================================
--- src/wp-admin/css/install.css	(revision 34441)
+++ src/wp-admin/css/install.css	(working copy)
@@ -61,6 +61,12 @@
 	font-variant: normal;
 }
 
+fieldset {
+	border: 0;
+	padding: 0;
+	margin: 0;
+}
+
 label {
 	cursor: pointer;
 }
Index: src/wp-admin/install.php
===================================================================
--- src/wp-admin/install.php	(revision 34441)
+++ src/wp-admin/install.php	(working copy)
@@ -177,8 +177,24 @@
 			<p><?php _e( 'Double-check your email address before continuing.' ); ?></p></td>
 		</tr>
 		<tr>
-			<th scope="row"><?php _e( 'Privacy' ); ?></th>
-			<td colspan="2"><label><input type="checkbox" name="blog_public" id="blog_public" value="1" <?php checked( $blog_public ); ?> /> <?php _e( 'Allow search engines to index this site' ); ?></label></td>
+		<th scope="row"><?php has_action( 'blog_privacy_selector' ) ? _e( 'Site Visibility' ) : _e( 'Search Engine Visibility' ); ?> </th>
+		<td><fieldset><legend class="screen-reader-text"><span><?php has_action( 'blog_privacy_selector' ) ? _e( 'Site Visibility' ) : _e( 'Search Engine Visibility' ); ?> </span></legend>
+		<?php if ( has_action( 'blog_privacy_selector' ) ) : ?>
+			<input id="blog-public" type="radio" name="blog_public" value="1" <?php checked( 1, $blog_public ); ?> />
+			<label for="blog-public"><?php _e( 'Allow search engines to index this site' );?></label><br/>
+			<input id="blog-norobots" type="radio" name="blog_public" value="0" <?php checked( 0, $blog_public ); ?> />
+			<label for="blog-norobots"><?php _e( 'Discourage search engines from indexing this site' ); ?></label>
+			<p class="description"><?php _e( 'Note: Neither of these options blocks access to your site &mdash; it is up to search engines to honor your request.' ); ?></p>
+			<?php
+			/** This action is documented in wp-admin/options-reading.php */
+			do_action( 'blog_privacy_selector' );
+			?>
+		<?php else : ?>
+			<label for="blog_public"><input name="blog_public" type="checkbox" id="blog_public" value="0" <?php checked( 0, $blog_public ); ?> />
+			<?php _e( 'Discourage search engines from indexing this site' ); ?></label>
+			<p class="description"><?php _e( 'It is up to search engines to honor this request.' ); ?></p>
+		<?php endif; ?>
+		</fieldset></td>
 		</tr>
 	</table>
 	<p class="step"><?php submit_button( __( 'Install WordPress' ), 'large', 'Submit', false, array( 'id' => 'submit' ) ); ?></p>
@@ -291,7 +307,7 @@
 		$admin_password = isset($_POST['admin_password']) ? wp_unslash( $_POST['admin_password'] ) : '';
 		$admin_password_check = isset($_POST['admin_password2']) ? wp_unslash( $_POST['admin_password2'] ) : '';
 		$admin_email  = isset( $_POST['admin_email'] ) ?trim( wp_unslash( $_POST['admin_email'] ) ) : '';
-		$public       = isset( $_POST['blog_public'] ) ? (int) $_POST['blog_public'] : 0;
+		$public       = isset( $_POST['blog_public'] ) ? (int) $_POST['blog_public'] : 1;
 
 		// Check email address.
 		$error = false;