commit 87f0075810b4db7fae23f69dbc86383b9305982e
Author: Martin Kulov <martin@kulov.net>
Date:   Sun Aug 7 21:16:28 2011 +0300

    single and double quotes on windows should be escaped with carret

diff --git a/includes/exec.inc b/includes/exec.inc
index c00154a..c37824e 100644
--- a/includes/exec.inc
+++ b/includes/exec.inc
@@ -233,10 +233,10 @@ function _drush_escapeshellarg_windows($arg) {
   $arg = preg_replace('/\\\/', '\\\\\\\\', $arg);
 
   // Escape double quotes.
-  $arg = preg_replace('/"/', '\\"', $arg);
+  $arg = preg_replace('/"/', '^"', $arg);
 
   // Escape single quotes.
-  $arg = preg_replace('/\'/', '\\\'', $arg);
+  $arg = preg_replace('/\'/', '^\'', $arg);
 
   // Add surrounding quotes.
   $arg = '"' . $arg . '"';