Please do NOT skip any line. Else the link will be missed and Book will not make sense. We go on building step by step. We give reference to many Books, Tools and web pages etc. While it is always nice to have self contained Books, the topic is so vast that, we have pointers to references. Second intention is to not repeat what is already mentioned by other Authors. We start with simple computer then move on to 8085/8086/x86 and present day computers. We discuss about systems programming parallel computers. We stop at classical computers. We do not dicuss Quantum computers intentionally. However, some good Books for Quantum computing are mentioned in this Book which can always be referred to. To re-iterate the focus is classical computers and their evolution and evolution of software along. We dicuss compilers at length. gcc and intel cc are discussed. We restrict the hardware to Intel family of chips because they are widely used. We refer 13 Books in this Book and critically review what is important in each of those Books. How they are relevant to this Book and so on. This Book is basically for very advanced users.Specifically people with advance knowledge of both software and hardware.