Completely revised and updated for all four new exams and reviewed and approved by CompTIA, this definitive volume covers everything you need to know to pass the CompTIA A+ Essentials exam and CompTIA A+ Exams 220-602, 220-603, and 220-604. Mike Meyers, the leading authority on CompTIA A+ certification and training, has helped hundreds of thousands of people pass the CompTIA A+ exams-and now he can help you too. Inside, you’ll find detailed coverage of the exam format, helpful exam tips, end-of-chapter practice questions, and hundreds of photographs and illustrations. After you ace the exams, this comprehensive guide will serve as an essential on-the-job reference.