Kurt Dillard's Study Guide for the 70-640 Exam helped me to pass and obtain the Microsoft MCTS Active Directory 2008, Configuring certification. After studying several Microsoft reference materials and practice tests, and still having trouble in a couple of areas, I picked up Kurt's Study Guide. Kurt explains the relevant facts to focus on for the certification test and presents it in a simple to understand format. At the end of each chapter, Kurt has questions and answers for you to check your comprehension. This is a great value and will surely help you to achieve your next certification! I look forward to referencing Kurt's other study guides.