diff --git a/core/trunk/index.php b/core/trunk/index.php
index 566ac7fec3689e8b0cb7a041591b637d288534bf..0fce31253d6f0056f913aabb465f9dfe58a15de9 100644
--- a/core/trunk/index.php
+++ b/core/trunk/index.php
@@ -36,6 +36,10 @@ $core = new core_tools();
 $_SESSION['custom_override_id'] = $core->get_custom_id();
 /**** retrieve HTTP_REQUEST FROM SSO ****/
 $_SESSION['HTTP_REQUEST'] = $_REQUEST;
+if (!file_exists('installed.lck')) {
+    header('location: install/index.php');
+    exit;
+}
 if(isset($_GET['origin']) && $_GET['origin'] == 'scan')
 {
     header('location: apps/'.$_SESSION['businessapps'][0]['appid'].'/reopen.php');
diff --git a/core/trunk/install/final.php b/core/trunk/install/final.php
index d9e7962b471c41e9a291354b22dac7e3a03159af..3119c65d8b1e98bbf88b89ebdc93605b7250df3a 100644
--- a/core/trunk/install/final.php
+++ b/core/trunk/install/final.php
@@ -1,6 +1,11 @@
 <?php
 include_once '../core/init.php';
 
+//write semaphore installed.lck
+
+$inF = fopen('installed.lck','w');
+fclose($inF);
+
 unset($_SESSION);
 $_SESSION = array();
 session_unset();