This book describes how software code analysis tools such as IDA Pro are used to disassemble programs written in high-level languages and recognise different elements of disassembled code in order to debug applications in less time. Also described are the basics of Assembly language programming (MASM) and the system and format of commands for the Intel microprocessor. Aspects of disassembling, analysing, and debugging software code are considered in detail, and an overview of contemporary disassemblers and debuggers used when analysing executable code is provided. The basics of working with these tools and their operating principles are also included, and emphasis is placed on analysing software code and identifying the main structure of those languages in which they were written.