Operating Systems

Computer hardware, such as the motherboard, CPU, adapter cards, display devices, and I/O devices, are only a part of the entire computer system. To make this hardware work, we need software that acts as an interface between human beings and the hardware. Software can be classified into three major categories as follows:

Operating systems

The operating system interacts directly with the computer hardware and provides a platform for applications and device drivers. It manages computer memory, input, output, disks, and filesystems.

Device drivers

Device drivers act as an interface between the operating system and the specific devices for which the driver software is written.


An application is the software program that takes commands from the user for a specific task, executes them, and produces the results.

The operating system is the primary software that makes the computer hardware usable. In this section, we will discuss some of the fundamentals of using operating systems, their installation and upgrade methods, troubleshooting techniques, and preventive maintenance procedures.

Overview of Operating Systems

Once we start discussing various operating systems, we certainly need to know about their revision levels. In this section, we will cover some basics of Microsoft Windows, Apple MAC, and Linux.


Microsoft Windows is no doubt the largest used operating system to date. This operating system evolved from Microsoft Disk Operating System (MS-DOS), which ...

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