Index: branches/version-2_13-dev/html/install/index.php
===================================================================
--- branches/version-2_13-dev/html/install/index.php	(revision 22968)
+++ branches/version-2_13-dev/html/install/index.php	(revision 23370)
@@ -23,5 +23,8 @@
 // ▼require.php 相当
 // rtrim は PHP バージョン依存対策
-define('HTML_REALDIR', rtrim(realpath(rtrim(realpath(dirname(__FILE__)), '/\\') . '/../'), '/\\') . '/');
+$GLOBALS['_realdir'] = rtrim(realpath(rtrim(realpath(dirname(__FILE__)), '/\\') . '/../'), '/\\') . '/';
+$GLOBALS['_realdir'] = str_replace('\\', '/', $GLOBALS['_realdir']);
+$GLOBALS['_realdir'] = str_replace('//', '/', $GLOBALS['_realdir']);
+define('HTML_REALDIR', $GLOBALS['_realdir']);
 
 require_once HTML_REALDIR . 'define.php';