CST-Computer Service Technician: The Definitive Guide to Software and Hardware Troubleshooting. *A comprehensive computer troubleshooting book that is used by Trade and Technical Schools for training students to become Computer Service Technicians. It is also used by thousands of experienced field service technicians who commonly refer to it as the ultimate computer reference book. You save 50% off the printed version by purchasing the eBook format. Yet you still have the ability to print a hard copy version to your printer.