Tips for the practical use of debuggers, such as NuMega SoftIce, Microsoft Visual Studio Debugger, and Microsoft Kernel Debugger, with minimum binding to a specific environment are disclosed in this debugger guide. How debuggers operate and how to overcome obstacles and repair debuggers is demonstrated. Programmers will learn how to look at what is inside a computer system, how to reconstruct the operating algorithm of a program distributed without source code, how to modify the program, and how to debug drivers.