This book investigates the hidden, undocumented application programming interfaces (APIs) within the Microsoft Windows operating system to reveal how software developers can leverage these internal functions. Andrew Schulman, a prominent software engineer and expert in reverse engineering, utilizes his extensive technical knowledge to deconstruct the Windows architecture. By analyzing binary code and system internals, he provides a framework for understanding how Windows applications interact with the kernel beyond the official documentation provided by Microsoft. The text serves as a technical manual for developers seeking to optimize performance and gain deeper control over the operating system environment.

Experts and systems programmers frequently cite this work as a foundational text for understanding the complexities of early Windows architecture. Readers often note the high level of technical density, which requires a strong background in assembly language and C programming to fully comprehend.