CompTIA A+ Core Certification: A Simple Guide To Operating Systems - Part 1

This guide covers the 11 A+ 220-1102 exam objectives related to operating systems, with a focus on the features, tools, versions, command-line tools, and configuration and installation of Microsoft Windows, as well as macOS and Linux operating systems.

These objectives may comprise 31 percent of the exam questions:
- Core 2 (220-1102): Objective 1.1: Identify basic features of Microsoft Windows editions.
- Core 2 (220-1102): Objective 1.2: Given a scenario, use the appropriate Microsoft command-line tool.
- Core 2 (220-1102): Objective 1.3: Given a scenario, use features and tools of the Microsoft Windows 10 operating system (OS).
- Core 2 (220-1102): Objective 1.4: Given a scenario, use the appropriate Microsoft Windows 10 Control Panel utility.
- Core 2 (220-1102): Objective 1.5: Given a scenario, use the appropriate Windows settings.
- Core 2 (220-1102): Objective 1.6: Given a scenario, configure Microsoft Windows networking features on a client/desktop.
- Core 2 (220-1102): Objective 1.7: Given a scenario, apply application installation and configuration concepts.
- Core 2 (220-1102): Objective 1.8: Explain common OS types and their purposes.
- Core 2 (220-1102): Objective 1.9: Given a scenario, perform OS installations and upgrades in a diverse OS environment.

- Core 2 (220-1102): Objective 1.10: Identify common features and tools of the macOS/desktop OS.
- Core 2 (220-1102): Objective 1.11: Identify common features and tools of the Linux client/desktop OS.

Many Windows versions have been used over the years, each bringing changes to features and appearances, but all the versions have used similar installation methods. For the 220-1102 A+ exam, the focus is on Windows 10, with previous versions being deprecated to legacy status. Windows 11 is not specifically mentioned in the objectives, although future editions of exam questions may refer to it. As noted in the A+ exam objectives:
Versions of Microsoft Windows that are not end of Mainstream Support (as determined by Microsoft), up to and including Windows 11, are intended content areas of the certification. As such, objectives in which a specific version of Microsoft Windows is not indicated in the main objective title can include content related to Windows 10 and Windows 11, as it relates to the job role.
Nonetheless, a description of key differences between Windows 10 and 11 is warranted and is included in this guide.
In this guide, you are introduced to the features and many options available both for installing Windows 10 on individual systems and for deployment to multiple computers. 


Understanding Common OS Types
220-1102: Objective 1.8: Explain common OS types and their purposes.
Different types of computers require different functionality from their operating systems. This section discusses differences between workstation and mobile operating systems and the file types they support.

Workstation OSs
Operating systems can be classified as open source, which refers to software that is effectively free to download and modify, and closed source, which refers to software that cannot be modified without express permission and licensing. Other terms used to describe closed source software are vendor specific, which means that only one company has access to the source code, and proprietary, which means that the software is owned and patented and can be used only with permission (and usually by paying a licensing fee).

Windows
Microsoft Windows is a closed source product and is the most widely used OS in the world. In the 1980s, when businesses transitioned into the digital age using IBM-compatible PCs, Microsoft usually provided the OS, which was known as the Disk Operating System (DOS). DOS is a command-line OS, which means that commands are entered as strings of text. DOS has since been replaced with Windows, which uses a graphical user interface (GUI) to allow commands to be entered with the click of a mouse. But the DOS legacy lives on with many of the same commands used in the PowerShell.
Windows has had many iterations over the years, but Windows 10 and perhaps 11 are the versions covered in the 220-1102 A+ exam.

Note: The following note in the CompTIA A+ exam objectives sets out guidelines for that content of Windows 11 when the 220-1101 and 220-1102 exams were released. Although Windows 11 is not specifically detailed in separate objectives, the following applies:
“Versions of Microsoft Windows that are not end of Mainstream Support (as determined by Microsoft), up to and including Windows 11, are intended content areas of the certification. As such, objectives in which a specific version of Microsoft Windows is not indicated in the main objective title can include content related to Windows 10 and Windows 11, as it relates to the job role.”

Apple Macintosh OS
macOS is the OS for Apple desktop products. As with Windows, macOS is closed source, and only some components are open to developers. macOS was released in 2016 and designed to integrate with devices using the iOS operating system, such as the iPhone, Apple TV, and Apple Watch. As of this printing, the latest version of macOS is Monterey, which is version 12.

Figure below shows the Monterey desktop.


macOS Monterey

Linux
Linux was derived from the UNIX operating system (used on mainframe computers predating PCs). It is named for Linus Torvalds, who developed Linux in 1991. Linux is an open source OS, which means that the source code is free. Many companies, such as Red Hat, modify Linux source code and then charge individuals and organizations to support the modifications.
Because Linux is open source, it is available free on the Web in the form of distros (distributions). Linux is available as command-line distros; and others are GUI distros. Popular distros of Linux are Ubuntu, Mint, Kali, and Red Hat.

Figure below shows a Linux Mint desktop environment.


Mint Desktop

Chrome OS
Chrome OS is a relatively new OS developed by Google. It is an open-source OS, based on an open-source Gentoo Linux OS. The functionality is unique, in that the OS runs off the Google Chrome web browser. Chrome OS can be installed off a USB drive and can run on a PC or Mac.
Chrome can run applications from Android, Linux, and Windows. When first released, Chrome OS ran Chromebook laptops that were inexpensive but also limited. Newer versions of Chromebooks and the Chrome OS offer better performance, but inexpensive versions are still available.

Cellphone/Tablet Operating Systems
Smartphones use typically either Android or iOS operating systems.
Some differences between Android and iOS smartphones include the following:
- Operating system updates are provided by the wireless carrier for Android phones.
- Wireless carriers provide network-specific updates for iPhones (iOS), but Apple provides the OS updates.

Android
Android, which is an operating system based on the Linux kernel, is an example of open source software. Used mostly on smartphones and tablet computers, Android is developed by the Open Handset Alliance, a group directed by Google. Google releases the Android OS code as open source, allowing developers to modify it and freely create applications for it. Google also commissioned the Android Open Source Project (AOSP), whose mission is to maintain and further develop Android.
Newer versions of Android are in constant development.
To determine the current version in use on a device, start at the Home screen (that is, the main screen that boots up by default). Tap the Menu button and then tap Settings. Scroll to the bottom and tap the About Phone (or About) option. Then tap Software Information or a similar option. Versions 1-10 were famously named after desserts, such as Lollipop (version 5) and Pie (version 9), but starting with version 10, the code names were dropped. As of this writing, the latest version is 12.
Unlike other mobile operating systems, Android licensing agreements allow for a great deal of customization of the finished product. Thus, Android smartphones and tablets from different vendors are likely to have different user interfaces and features.
iOS

The Apple iOS is an example of closed source software.
Known as the iPhone Operating System, this is now simply referred to as iOS because it is used on the iPod Touch, and iPhone. iOS is based on macOS (used on Mac desktops and laptops) and, therefore, has its roots in UNIX. Figure below shows the Home screen of an iPad Mini 2 running iOS version 9.0.1.


iPad Mini 2 Home Screen

The iPad once ran on iOS, but with version 13 (2019), it was powerful enough to have its own iPadOS, which is more robust than iOS and supports using a keyboard and multitasking.
To determine the version of iOS a device is running, go to the Home screen and tap Settings General About. For example, the figure below shows an iPhone running version 15.1. iPad 15 was released in fall 2021 for iPad Pro, iPad (fifth generation onward), iPad Mini (fourth generation onward), and iPad Air (second generation onward).


iPhone Using Version 15.1 of iOS

Unlike Android, iOS is not open source. Only Apple hardware uses this operating system.

Various File System Types
What exactly is a file system? A file system determines how data and drives are organized, but it is also a general term for how an operating system stores various types of files. As discussed earlier in this guide, Windows supports three different file systems for hard drives and USB flash drives: FAT32, NTFS, and exFAT.

The New Technology File System (NTFS) is the native file system of Windows 10. NTFS has many differences from FAT32, including the following:
- Access control: Different levels of access control, by group or user, can be configured for both folders and individual files.
- Built-in compression: Individual files, folders, or an entire drive can be compressed without the use of third-party software.
- Individual Recycle Bins: Unlike FAT32, NTFS includes a separate Recycle Bin for each user.
- Support for the Encrypting File System (EFS): The Encrypting File System (EFS) enables data to be stored in an encrypted form. It requires no password and no access to files.
- Support for mounting a drive: Drive mounting enables you to address a removable-media drive’s contents, possibly as if its contents are stored on your hard drive. The hard drive’s drive letter is used to access data on both the hard drive and the removable media drive.
- Disk quota support: The administrator of a system can enforce rules about how much disk space each user is allowed to use for storage.
- Hot-swapping: Removable-media drives that have been formatted with NTFS (such as USB) can be connected or removed while the operating system is running.
- Indexing: The indexing service helps users locate information more quickly when the Search tool is used.

Follow these steps to determine what file system was used to prepare a Windows hard drive:
Step 1. Open Windows File Explorer.
Step 2. Right-click the drive letter in the Explorer window and select Properties.

The properties sheet for the drive lists NTFS for a drive prepared with NTFS and FAT32 for a drive prepared with FAT32 (see Figure).


A Hard Drive Formatted with NTFS Version 5 (Left) and a Flash Memory Drive Formatted with FAT32 (Right)

During installation, Windows 10 automatically formats the partitions created by the partition process with NTFS.
exFAT, FAT32, and NTFS are common Windows files systems. Table 6-8 briefly describes these and other file systems that perform the same tasks but on different operating systems.

Table: File System Format Comparison

Vendor Life-Cycle Limitations
The economic concept of planned obsolescence applies to computers and OSs even more so than in other commercial products. When a CPU, computer model, or OS update is rolled out, chances are very good that its replacement model is well into the development stage. Two concepts discussed in this section are end of life (EOL) and product life cycle.

End of Life (EOL)
Most customers demand that computer manufacturers stay on the leading edge of technology in their products. Quality of experience and security concerns are central to keeping customers loyal. But the market has only so much capacity; with each new version of a product or OS, an old one is usually assigned “deprecated” or “legacy” status. When a new product is released, such as a CPU rollout or GPU card, the EOL is already planned because the next generation is usually well into development. This is true of both hardware and OS updates. For example, Windows 7 is already EOL, and the Windows 8 EOL is scheduled for January 2023. Windows 10 EOL is currently scheduled for October 2025.
 

Update Limitations
Not all OS updates are feasible on all products. For example, iOS 15 cannot run on most phone models earlier than iPhone 6s or SE. This is because the software advancements went further than the physical capabilities of the chipset—this can be processing power, video power, or another factor. Be sure to check vendor websites before updating, to make sure the device is compatible with the update.
Updating can have hidden costs as well. If users have accessories to go with their devices—video cable, USB adapters, and writing pens, those might also need to be replaced. As devices migrate to USB-C interfaces, many of the old accessories are rendered useless when the new device arrives.

Vendor-Specific Limitations/Compatibility Concerns Between OSs
Nearly all smartphones in the United States use either Android or iOS. Each OS has loyal users, and the debate over which is better has proponents on both sides. Both are good systems, but several considerations are involved when choosing between the vendor-specific, closed source Apple iOS and the open source Android OS.
One can argue that because Apple has control of iOS, it can better control the quality and safety of Apple products. In addition, Apple can develop better applications, such as iMessage, Find My Friends, and FaceTime, that work well because they can be designed around the advantages of a closed source platform. Although it is an advantage for a family or an organization to use common apps to communicate and share data easily, non-iPhone users are out of the loop with such apps.
One can also argue that Android has certain advantages because it has more apps available. Additionally, Android devices tend to be much less expensive than iPhones. Android allows third-party apps, but some people see third-party apps as a security problem instead of an advantage.
The good news is that both iOS and Android are robust and reliable systems. The best choice ultimately depends on the users and their communication needs. More good news is that some apps coming on the market enable easy communication and sharing between Android and iOS users.

Best Practices
To maintain any computer system, you should follow best practices related to the following:
- Scheduled backups
- Scheduled disk maintenance
- System updates and the App Store
- Patch management
- Driver and firmware updates
- Antivirus and anti-malware updates

The following sections discuss best practices in these areas for macOS and Linux.
Scheduled Backups
Scheduled backups help prevent major data loss in case of system failure, accident, or loss. Backups can be used to safeguard the following:
- Contacts
- Email
- Media files (photos, videos, and music)
- Documents

The default backup app in macOS is Time Machine. Linux includes several utilities that can be used for backups. These include the command-line tar and rsync utilities. Others, including the grsync (GUI for rsync) and duplicity (command line and GUI available as Déjà Dup), are available from the repository for a Linux distribution or from the vendors.

Note: The BackupYourSystem page on Ubuntu Linux Help (https://help.ubuntu.com/community/BackupYourSystem) provides a long list of command-line and GUI-based backup tools that also work with other Linux distros.
Scheduled backups should be run at times when the system is idle, such as overnight and on weekends.

Backup Types
A full backup backs up the entire contents of the computer or selected drive to another local or network location. A backup program can create a compressed file to store backed-up information. With this type of backup, the backup program must run a restore utility to make the files usable again. Another type of backup program simply copies backup files to a different location, where they can be opened by the operating system.
Most backup programs can also run an incremental backup, which backs up only the files that have been created or changed after the last full

backup.
Backup features to look for include the following:
- Compression: This reduces the amount of file space and often also decreases the amount of time needed to make a backup.
- Support for incremental as well as full backups: Good backup practice calls for periodic full backups followed by backups of files that have changed since the last full backup (incremental backups).
- Local and network backup destinations: Some backup utilities might require additional configuration before a network backup can be performed.

Configuring a Backup App in Linux
The Ubuntu distributions have a preinstalled backup application that runs weekly and can also be configured to run daily. Backups can be kept as long as space permits, or for at least 6 months or a year. This backup utility is designed for new users.
Backup utilities based on tar, rdiff, and other Linux apps can require a great deal of scripting. One backup utility that helps create backup scripts by filling in the blanks is Backupninja. More information on Backupninja can be found at https://linux.die.net/man/1/backupninja.

Antivirus
It’s widely believed that Linux is immune to viruses and malware. Although Linux is not targeted nearly as much as Windows, an unprotected Linux computer can be used as an infection vector for Windows machines that connect to it.
ClamAV (www.clamav.net) is an open source antivirus app available for both macOS and Linux. Scans and updates can be automated with cron, and a GUI front end known as ClamTK also is available. Well-known antivirus software usually has Linux and macOS versions as well as Windows versions.
Antivirus and anti-malware apps for Linux should be updated at least daily.
 

Updates and Patches
If an organization has only a few Linux systems, running manual system updates with yum or apt-get might be sufficient for patch management. However, as the number of Linux systems increases, and when Linux systems are used for mission-critical functions such as web servers, better patch management methods are desirable.
If you use a script to check for and install updates to Linux or installed apps, the crontab utility can be used to set the task on a schedule that is run by the cron utility.

Tools
As with Windows and macOS, key tools add ease and functionality to the OS. Two important tools in Linux are discussed here.
shell/terminal
The terminal and shell tools in Linux are similar to the command shell (prompt) and PowerShell tools in Windows. The command line is the most direct and efficient access to the center of the OS, and PowerShell was designed to extend the power of the command shell, adding scripting functions and interoperability. The same is true of Linux. The terminal command opens a shell for typing commands. Linux shells, of which there are several, add similar functionality to the Linux terminal. The most popular Linux shell is Bash (Bourne Again Shell), but others are in use; these include PowerShell, which is now a fully functional cross-platform scripting language that works in Linux, macOS, and Windows 10 and 11.
To open Terminal in Linux, simply press Ctrl+Alt+T or type terminal in the search box.

Samba
Linux and Windows machines can work together on a network, thanks to Samba. Samba is open source software that enables Linux machines to work in a Windows environment for file and print sharing. Samba also enables Linux machines to participate in Windows Active Directory as a controller or a member. More information on Samba is available at www.samba.org/.

Key Topics To Know about Operating Systems:

Basic Features of Microsoft Windows Editions
Windows 10 Editions
Feature Differences
Domain Access vs. Workgroup
Desktop Styles/User Interface
Remote Desktop Connection and Remote Assistance
Random Access Memory (RAM)
BitLocker
Group Policy Editor
Upgrade Paths
Microsoft Command-Line Tools
Starting a Command Prompt Session with Windows PowerShell
Commands Available with Standard Privileges vs. Administrative Privileges

Windows Command-Line Commands:
format
copy
xcopy
robocopy
diskpart
sfc
chkdsk
gpupdate
gpresult
pathping

Microsoft Windows 10 Operating System (OS) Features and Tools
Task Manager
Microsoft Management Console (MMC) Snap-in
Event Viewer
Disk Management
Task Scheduler
Device Manager
Certificate Manager
Local Users and Groups
Performance Monitor
Additional Tools
System Information (msinfo32)
Resource Monitor
System Configuration Utility
Disk Cleanup
Disk Defragment/Optimize Drives
Registry Editor
Windows 10 Control Panel Utilities
Starting Control Panel
Internet Options
User Accounts
Device Manager
Indexing Options
Administrative Tools
File Explorer Options
Power Options
Hibernate
Power Plans
Sleep/Suspend
Standby, Lid, and Fast Startup Options
Universal Serial Bus (USB) Selective Suspend
Ease of Access
Windows Settings
Time and Language
Update and Security
Personalization
Apps
Privacy
System
Devices
Network and Internet
Gaming
Accounts
Microsoft Windows Networking Features on a Client/Desktop
Workgroup vs. Domain Setup
Workgroup Networking
Creating a Workgroup
Domain Setup
Network Shares
Administrative Shares
Sharing a Folder
Mapped Drives
Printer Sharing vs. Network Printer Mapping
Local OS Firewall Settings
Client Network Configuration
Internet Protocol (IP) Addressing Scheme
Subnet Mask
Domain Name System (DNS) Settings
Gateway
Static vs. Dynamic
Establish Networking Connections
VPN Connections
Wireless Connections
Wired Connections
WWAN (Cellular) Connections
Proxy Settings
Public Network vs. Private Network
File Explorer Navigation: Network Paths
Metered Connections and Limitations
Installation and Configuration Concepts
System Requirements for Applications
32-Bit vs. 64-Bit File Systems
FAT32
exFAT (FAT64)
32-Bit vs. 64-Bit Dependent Application Requirements
Dedicated Graphics Card vs. Integrated Graphics Card
Video Random Access Memory (VRAM) Requirements
RAM Requirements
Central Processing Unit (CPU) Requirements
External Hardware Tokens
Storage Requirements
OS Requirements for Applications
Application-to-OS Compatibility
32-Bit vs 64-Bit OS
Distribution Methods
Physical Media vs. Downloadable
Other Considerations for New Applications
Understanding Common OS Types
Workstation OSs
Windows
Apple Macintosh OS
Linux
Chrome OS
Cellphone/Tablet Operating Systems
Android
iOS
Various File System Types
Vendor Life-Cycle Limitations
End of Life (EOL)
Update Limitations
Vendor-Specific Limitations/Compatibility Concerns Between OSs
OS Installations and Upgrades in a Diverse OS Environment

Boot Methods
Types of Installations
Unattended Installation
Types of Installations
Upgrades
Clean Install
Repair Installation
Remote Network Installation
Image Deployment
Recovery Partition
Refresh/Restore
Other Considerations/Third-Party Drivers
Partitioning Methods
Partitioning Overview
MBR vs. GPT Partition Types
Disk Preparation Using MBR
Partitioning Using GPT
Dynamic and Basic Disks
Creating Partitions During Windows Installation
Formatting
Upgrade Considerations
Backup Files and User Preferences
Application and Driver Support/Backward Compatibility
Hardware and Application Prerequisites and Compatibility
Feature Updates
Update Life Cycle

Common Features and Tools of the macOS/Desktop OS
Installation and Uninstallation of Applications
File Types
App Store
Uninstallation Process
Apple ID and Corporate Restrictions
Best Practices
Backups
Antivirus/Anti-malware Updates
Updates/Patches
System Preferences
Features
Disk Utility
FileVault
Terminal
Force Quit

Common Features and Tools of the Linux Client/Desktop OS
Common Linux Commands:
ls
grep
cd
shutdown
pwd
mv
cp
rm
chmod
chown
su/sudo
apt-get
YUM (Yellowdog Updater, Modified)
ip
df (Disk Free)
ps
man
top
find
DIG (Domain Information Groper)
cat
nano

Best Practices:
Scheduled Backups
Antivirus
Updates and Patches
Tools
shell/terminal
Samba