diff --git a/wp-settings.php b/wp-settings.php
index faedd3718..9dd4269c0 100644
--- a/wp-settings.php
+++ b/wp-settings.php
@@ -27,11 +27,26 @@ if ( ! isset($blog_id) )
 
 // Fix for IIS, which doesn't set REQUEST_URI
 if ( empty( $_SERVER['REQUEST_URI'] ) ) {
-	$_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME']; // Does this work under CGI?
 
-	// Append the query string if it exists and isn't null
-	if (isset($_SERVER['QUERY_STRING']) && !empty($_SERVER['QUERY_STRING'])) {
-		$_SERVER['REQUEST_URI'] .= '?' . $_SERVER['QUERY_STRING'];
+	// IIS Mod-Rewrite
+	if (isset($_SERVER['HTTP_X_ORIGINAL_URL'])) {
+		$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_ORIGINAL_URL'];
+	}
+	// IIS Isapi_Rewrite
+	else if (isset($_SERVER['HTTP_X_REWRITE_URL'])) {
+		$_SERVER['REQUEST_URI'] = $_SERVER['HTTP_X_REWRITE_URL'];
+	}
+	else {
+		// If root then simulate that no script-name was specified
+		if (empty($_SERVER['PATH_INFO']))
+			$_SERVER['REQUEST_URI'] = substr($_SERVER['SCRIPT_NAME'], 0, strrpos($_SERVER['SCRIPT_NAME'], '/')) . '/';
+		else
+			$_SERVER['REQUEST_URI'] = $_SERVER['SCRIPT_NAME'] . $_SERVER['PATH_INFO'];
+			
+		// Append the query string if it exists and isn't null
+		if (isset($_SERVER['QUERY_STRING']) && !empty($_SERVER['QUERY_STRING'])) {
+			$_SERVER['REQUEST_URI'] .= '?' . $_SERVER['QUERY_STRING'];
+		}
 	}
 }