http://www.microsoft.com/learning/mc...hance/details/
Now, you can get a free second shot at any Microsoft Learning IT Professional, Developer, or Microsoft Dynamics (formerly Microsoft Business Solutions) exam.
To participate, register for the second shot offer before you take any exam. You'll receive a promotion code that is good for one free second shot at the same exam in case you don't pass it on your first try. There's no limit per customer, so after you've registered, you'll be entitled to one free retake of any exam that you sign up for.