We often see big smiles after a big achievement. It is expressed as one kind of victory. "Clearing an interview" is considered as such an achievement. It is a "Dream comes true" experience that was eagerly wanted by that person. But unfortunately, most of the time, we ensure the failure much before the interview begins by lack of preparation, some unknown fears and lack of our self-confidence. Sometimes we discover that this pattern is very much common. Thanks to my great teachers, my successful seniors and my true friends -through them I have learned about a simple key. In this book, I have given you the key to pass (my best wishes are with you) a Computer Science interview where Operating System (OS) can be your guide to crack that interview. On successful completion of the book, you can easily handle all the obstacles mentioned earlier.And here is the key: most of the time a true interviewer asks you the fundamental questions. He/she knows that anyone can develop a specialized knowledge if the fundamentals are clear to that interviewee. But unfortunately most of the time, a candidate spend most of his/her time on the tough questions -answers of which are not easy to remember if the foundation is weak.So, with this book, you will have an opportunity to check your fundamentals, to gain a huge confidence and to remove unknown fears before appearing in such an interview. Author has made his best effort to answer these questions by his own knowledge and different reliable materials available in the market. So, we believe that you will enjoy the book.