diff --git a/phpBB/adm/index.php b/phpBB/adm/index.php
index 0c317d3d4c..336afc0de1 100644
--- a/phpBB/adm/index.php
+++ b/phpBB/adm/index.php
@@ -11,6 +11,7 @@
 /**
 */
 define('IN_PHPBB', 1);
+define('ADMIN_START', 1);
 define('NEED_SID', true);
 
 // Include files
diff --git a/phpBB/adm/style/acp_main.html b/phpBB/adm/style/acp_main.html
index d68e9d2547..a3a3e90c00 100644
--- a/phpBB/adm/style/acp_main.html
+++ b/phpBB/adm/style/acp_main.html
@@ -11,6 +11,13 @@
 	</div>
 <!-- ENDIF -->
 
+<!-- IF S_REMOVE_INSTALL -->
+	<div class="errorbox">
+		<h3>{L_WARNING}</h3>
+		<p>{L_REMOVE_INSTALL}</p>
+	</div>
+<!-- ENDIF -->
+
 <table cellspacing="1">
 	<caption>{L_FORUM_STATS}</caption>
 	<col class="col1" /><col class="col2" /><col class="col1" /><col class="col2" />
diff --git a/phpBB/common.php b/phpBB/common.php
index d52cf8c884..c69ee4395e 100644
--- a/phpBB/common.php
+++ b/phpBB/common.php
@@ -191,10 +191,11 @@ unset($dbpasswd);
 $config = $cache->obtain_config();
 $dss_seeded = false;
 
-// Warn about install/ directory
-if (file_exists($phpbb_root_path . 'install'))
+// Disable board if the install/ directory is still present
+if (file_exists($phpbb_root_path . 'install') && !defined('ADMIN_START'))
 {
-	trigger_error('REMOVE_INSTALL');
+	$message = (!empty($config['board_disable_msg'])) ? $config['board_disable_msg'] : 'BOARD_DISABLE';
+	trigger_error($message);
 }
 
 ?>
\ No newline at end of file
diff --git a/phpBB/includes/acp/acp_main.php b/phpBB/includes/acp/acp_main.php
index 81c265581b..bab08bc0ff 100644
--- a/phpBB/includes/acp/acp_main.php
+++ b/phpBB/includes/acp/acp_main.php
@@ -456,6 +456,12 @@ class acp_main
 			$template->assign_var('S_DEBUG_EXTRA', true);
 		}
 
+		// Warn if install is still present
+		if (file_exists($phpbb_root_path . 'install'))
+		{
+			$template->assign_var('S_REMOVE_INSTALL', true);
+		}
+
 		$this->tpl_name = 'acp_main';
 		$this->page_title = 'ACP_MAIN';
 	}