A+: Is a Problem Is Caused by Hardware or Software

The oldest dilemma for any computer technician is determining whether a problem is caused by hardware or software. The widespread use of Windows operating systems makes this problem even more acute than it was when MS-DOS was the predominant standard, because all hardware in a Windows system is controlled by Windows device drivers.

A troubleshooting cycle is a method that you can use to determine exactly what part of a complex system, such as a computer, is causing the problem. The troubleshooting cycle used in this section goes into more depth than the CompTIA six-step troubleshooting process. The first step is to determine the most likely source of the problem. The client interview will help you determine which subsystem is the best place to start solving the problem. In the previous example, the printing subsystem was the most likely place to start.

A subsystem is the combination of components designed to do a particular task, and it can include hardware, software, and firmware components. 

For example, for the printing subsystem: 

Software: Printer driver in Windows app

Hardware: Printer, cable, parallel, serial, USB or network port

Firmware: BIOS configuration

Display subsystem software: Video drivers in Windows

Hardware: Video card (unless motherboard has integrated video), monitor, cables, port type 

Firmware: Video BIOS, BIOS configuration of video, boot priority

Audio subsystem software:  Audio drivers in Windows

Hardware: Sound card (unless motherboard has integrated audio), cables, speaker, mike, cables from CD/DVD

Firmware:  BIOS configuration for integrated audio

Mouse/pointing device subsystem software:  drivers in Windows

Hardware: Mouse or pointer device, serial or mouse port, USB port

Firmware:   BIOS port configuration, USB legacy configuration

Keyboard subsystem software:  drivers in Windows

Hardware: Keyboard, PS/2 or USB port

Firmware:   BIOS keyboard configuration, USB legacy configuration

Storage subsystem software:  drivers in Windows

Hardware: Drives, cables, power cables, drive interface card or built-in ports

Firmware:   BIOS drive configuration for PATA, SATA, USB, IEEE-1394, RAID