Index: wp-admin/install.php
===================================================================
--- wp-admin/install.php	(revision 25005)
+++ wp-admin/install.php	(working copy)
@@ -190,7 +190,7 @@
 		display_header();
 		// Fill in the data we gathered
 		$weblog_title = isset( $_POST['weblog_title'] ) ? trim( wp_unslash( $_POST['weblog_title'] ) ) : '';
-		$user_name = isset($_POST['user_name']) ? trim( wp_unslash( $_POST['user_name'] ) ) : 'admin';
+		$user_name = isset($_POST['user_name']) ? trim( wp_unslash( $_POST['user_name'] ) ) : '';
 		$admin_password = isset($_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'] ) ) : '';