If you really want to troubleshoot computers, this book provides the foundation you need. You get to build a computer from scratch using simulators. It takes you from GATE LOGIC through OPERATING SYSTEMS More on: The Elements of Computing Systems / Nisan & Schocken
I am really enjoying this book. I recommend you read the Preface up to Boolean logic in the sample for a solid understanding of what goes on inside your computer. The hierarchy chart alone was quite an eye opener.
Simulation software used to "build" a computer. http://www.nand2tetris.org/software.php
Thank you Noam Nisan
Steve
Note: Chinese Edition: 2006 also available