FREE CompTIA A+ Study Guide 2026: Core 1 & Core 2

This free CompTIA A+ study guide covers everything the certification tests across both core exams — Core 1 (220-1201) and Core 2 (220-1202) — organized to CompTIA’s current V15 exam objectives.^[1]

It’s interactive, not a wall of text: every module has built-in checkpoint quizzes, labeled diagrams, flashcards, and practice questions, so you learn by doing — not just reading.

The A+ is one certification you earn by passing two exams. Together they span nine official domains — five in Core 1 (hardware, networking, mobile, virtualization/cloud, and troubleshooting) and four in Core 2 (operating systems, security, software troubleshooting, and operational procedures).

We teach all nine in seven study modules and lead with the heaviest-weighted content. Read a module, test yourself at each checkpoint, then drill gaps with our free practice test and flashcards. This is a high-yield overview mapped to the official objectives — not a full IT textbook.

CompTIA A+ is one of the 14 CompTIA certifications — explore our CompTIA study guides to compare and prep across the whole family.

CompTIA A+ Exam Snapshot

The A+ is earned by passing two separate core exams. Each core has its own questions, time limit, and passing score:

Core 1 is the hardware-and-infrastructure half; Core 2 is the software, operating-systems, and security half. Study each core to its own weighting:^[1]

Module 1 · Hardware (Core 1)

25% of Core 1 — the largest single content domain on Core 1. This module covers the physical components of a PC: how to identify, install, and configure cables, memory, storage, motherboards, CPUs, power, and printers.

1.1 Cables, Connectors & RAM

Start with memory. RAM is fast, volatile working memory; today’s standard is DDR5, which is keyed differently from DDR4 and is not interchangeable.

Laptops use the smaller SODIMM form factor. Servers and workstations use ECC RAM to catch single-bit errors. On the connector side, know your video (HDMI, DisplayPort, VGA), data (USB-C/Thunderbolt, USB-A), and internal connectors (SATA, the 24-pin and CPU power).

1.2 Storage & RAID

Storage is high-yield. An SSD has no moving parts and is far faster than a spinning HDD. The fastest SSDs are NVMe drives on M.2 slots running over PCIe, reaching multiple GB/s; SATA SSDs top out near 600 MB/s. For fault tolerance, combine drives with RAID.

1.3 Motherboards, CPUs & BIOS/UEFI

The motherboard ties everything together. Form factors run ATX → microATX → Mini-ITX (smaller = fewer slots). The CPU mounts in a socket (Intel LGA / AMD AM4 PGA or AM5 LGA).

Firmware — BIOS/UEFI — runs the POST at power-on, then hands off to the boot loader. UEFI adds Secure Boot, a GUI, and support for >2 TB GPT disks. The TPM stores encryption keys and is required for BitLocker and Windows 11.

1.4 Power & Printers

The PSU converts AC to the DC rails (+3.3V, +5V, +12V) the system needs; the +12V rail powers the CPU, GPU, and drives. Match wattage to the build and prefer an 80 PLUS-rated supply. Printers are a guaranteed topic — know the laser imaging process and the four main printer types.

Module 2 · Networking (Core 1)

23% of Core 1. This module covers how devices get addresses and talk to each other — TCP/IP, the well-known ports and protocols, network hardware, wireless, and small-office/home-office setup.

2.1 TCP/IP & Addressing

Every device on a network needs an IP address. IPv4 is 32-bit (e.g., 192.168.1.10); IPv6 is 128-bit. A Subnet mask (e.g., 255.255.255.0 = /24) marks which addresses share the local network, and the default gateway is the router used to reach other networks.

DHCP hands out these settings automatically; DNS resolves names to addresses. When DHCP fails, a host self-assigns an APIPA (169.254.x.x) address — your top clue for “no connectivity.” NAT lets many private addresses share one public IP.

2.2 Ports & Protocols

Ports and protocols are among the most-tested A+ topics. First, the transport layer: TCP is reliable and ordered (web, email, files), while UDP is fast and connectionless (streaming, VoIP, DNS). Then memorize the well-known ports cold — and always prefer the encrypted version of a protocol.

2.3 Network Hardware & Wireless

A Switch forwards frames within a LAN by MAC address; a Router forwards packets between networks by IP. A managed switch adds VLANs, QoS, and config. PoE carries power and data on one Ethernet cable to access points and cameras.

On wireless, know the bands (2.4 GHz = range, 5/6 GHz = speed), the 802.11 standards (n/ac/ax/be), and always secure Wi-Fi with WPA3 (never WEP). The mnemonic for where these devices live is the OSI model:

2.4 SOHO & IoT

For a small office/home office, you configure the all-in-one router: set a strong SSID and WPA3 passphrase, use DHCP (with reservations for servers/printers), and use port forwarding to expose an internal service. Place IoT devices (smart plugs, cameras, doorbells, assistants) on a separate, segmented network so a compromised gadget can’t reach your PCs. Know the internet connection types too.

Module 3 · Mobile, Virtualization & Cloud (Core 1)

Two official domains, 24% of Core 1 combined: Mobile Devices (13%) and Virtualization & Cloud Computing (11%). This module covers laptop/mobile hardware and connectivity, plus how virtualization and cloud services work.

3.1 Laptop & Mobile Hardware

Laptops pack the same components into a small chassis. Know the field-replaceable parts: battery (a swollen Li-ion battery is a safety hazard — replace and recycle, never puncture), RAM (SODIMM), storage (M.2/NVMe), Wi-Fi/cellular cards (Mini PCIe/M.2), the display assembly, and the digitizer (the touch layer). The Fn key toggles secondary functions like brightness, volume, wireless, and external display.

3.2 Mobile Connectivity & Sync

Mobile devices connect over cellular (LTE/5G), Wi-Fi, Bluetooth (peripherals), and NFC (tap-to-pay). A phone can share its data via a hotspot or tethering. Airplane mode kills all radios at once.

For email, prefer IMAP (syncs across devices) over POP3 (downloads to one). Devices sync to the cloud, a desktop, or a car; corporate fleets are controlled by MDM (Mobile Device Management), which enforces encryption, policy, and remote wipe.

3.3 Virtualization & Cloud

A Hypervisor runs virtual machines on shared hardware: Type 1 (bare-metal, e.g., ESXi/Hyper-V) and Type 2 (on a host OS, e.g., VirtualBox). Each VM needs adequate CPU, RAM, storage, and CPU virtualization support (Intel VT-x / AMD-V) enabled in firmware. Cloud builds on this with three service models:

Module 4 · Hardware & Network Troubleshooting (Core 1)

28% of Core 1 — the single biggest domain on either core. Everything here rests on one process: CompTIA’s six-step troubleshooting methodology. Learn it cold; questions phrase symptoms and ask for the right next step.

4.1 The 6-Step Methodology

This is the most important diagram in the whole guide — and the most-tested process on the A+.

4.2 Hardware, Storage & Display Symptoms

Map symptoms to causes. A burning smell or smoke means power off immediately (a PSU/capacitor hazard). Thermal shutdowns and throttling point to cooling — dust, a loose heatsink, or dried thermal paste.

Grinding/clicking from a drive or a S.M.A.R.T. error means back up now and replace the disk. No video? Check the monitor, cable, and input; reseat the GPU/RAM; try integrated graphics.

4.3 Network Symptoms

For network problems, work top-down with the command-line tools. Check link lights first, then run ipconfig (a 169.254 address = DHCP failed). Use ping to test reachability, tracert to find where the path breaks, and nslookup to test DNS.

Module 5 · Operating Systems (Core 2)

28% of Core 2 — tied for the largest Core 2 domain. This module covers Windows editions and features, the command line and admin tools, macOS and Linux basics, and OS installation.

5.1 Windows Editions & Features

Windows comes in Home, Pro, Pro for Workstations, and Enterprise. The features that separate Pro+ from Home are the exam favorites: BitLocker (full-disk encryption), Active Directory domain join, and Group Policy. File systems matter too: NTFS (permissions, encryption, journaling) vs FAT32 (4 GB file limit) vs exFAT.

5.2 Command Line & Admin Tools

Know the Windows command line and the MMC/admin tools by what each one fixes.

5.3 macOS & Linux

Core 2 expects basic macOS and Linux literacy. On macOS know Time Machine (backups), Spotlight (search), Mission Control/Spaces, Disk Utility, and FileVault (encryption). On Linux, know the core shell commands.

5.4 Install & Configure

For installs, know the methods (USB, optical, network PXE) and the partitioning schemes: MBR (legacy, max 2 TB) vs GPT(UEFI, >2 TB, many partitions). An in-place upgrade keeps apps/data; a clean install wipes the drive (back up first). Recovery tools include WinRE, System Restore, and Safe Mode.

Module 6 · Security (Core 2)

28% of Core 2 — tied for the largest Core 2 domain. Security spans the goals of security, malware, social engineering, wireless and authentication, and securing the OS.

6.1 Security Concepts & Malware

Every control supports the CIA triad — Confidentiality, Integrity, Availability — and the principle of Least privilege. Then know the malware zoo by behavior.

6.2 Social Engineering & Threats

People are the most-exploited attack surface. Social engineering manipulates them. Phishing leads the list — and its variants are heavily tested.

6.3 Wireless & Authentication

Secure wireless with WPA3 (WPA2-AES is acceptable; WEP is broken; disable WPS). For identity, use MFA — two or more factors of different types (know, have, are).

6.4 Securing the OS & Best Practices

Harden endpoints with UAC, standard (least-privilege) accounts, host firewalls, anti-malware/EDR, screen locks, and BitLocker for data at rest. Encrypt data in transit with HTTPS and a VPN. When disposing of drives, a standard format leaves data recoverable — use secure erase/overwrite, degaussing, or physical destruction for sensitive data.

Module 7 · Software Troubleshooting & Operations (Core 2)

Two official domains, 44% of Core 2 combined: Software Troubleshooting (23%) and Operational Procedures (21%). This module covers fixing OS/app/mobile problems, removing malware safely, and the professional procedures every tech follows.

7.1 OS & Application Troubleshooting

Software problems follow the same six-step methodology. A Windows Blue Screen (BSOD) or a macOS spinning pinwheel signals a crash — check recent driver/update changes, run diagnostics, review logs, and boot to Safe Mode.

For a crashing app: repair/reinstall it, update it and the OS, check compatibility, and clear its cache. Slow performance? Check Task Manager, startup apps, malware, disk space, and overheating.

7.2 Malware Removal

CompTIA defines a specific best-practice order for removing malware — and the order is tested.

7.3 Mobile & Security Troubleshooting

Mobile problems have their own playbook: clear app cache/data and update for crashes; check battery usage by app and replace a swollen battery for drain/overheating; toggle airplane mode or reset network settings for connectivity. Mobile malware shows as high data use, unexpected ads, and fake apps — install only from official stores. Security symptoms (rogue ads, leaked data, certificate warnings) tie back to the malware and social-engineering content in Module 6.

7.4 Operational Procedures

The professional side of the job. Safety first: control ESD with antistatic straps/mats, follow the SDS for chemical and battery/toner disposal, use a Class C extinguisher on electrical fires, and protect power with a surge protector or a UPS. Then the process disciplines: Change management, the 3-2-1 backup rule, ticketing/knowledge-base documentation, asset management, scripting, and professional communication and data privacy.

How to Use This CompTIA A+ Study Guide

The A+ is two exams, so plan for two pushes. The most efficient path to passing both:

• Tackle one core at a time. Modules 1–4 are Core 1 (220-1201); Modules 5–7 are Core 2 (220-1202). Many people pass Core 1 first, then Core 2.
• Study by weight. In Core 1 lead with Troubleshooting (28%), Hardware (25%), and Networking (23%). In Core 2, Operating Systems and Security tie at 28% each.
• Master the two big procedures. The 6-step troubleshooting methodology and the 7-step malware removal order appear constantly — memorize both.
• Check off as you go. Use the Study Guide Contents to mark each section done; it raises your exam-readiness score.
• Take every checkpoint, then drill. Send weak domains into the flashcards and a practice test until the score climbs.

CompTIA A+ Glossary

The high-yield CompTIA A+ terms in one place — hover any dotted term in the guide, or flip the whole deck here as a self-grading flashcard set.

3-2-1 backup rule

Keep 3 copies of data, on 2 media types, with 1 offsite — a resilient backup strategy.

Active Directory

Microsoft's directory service for centralized authentication, accounts, and policy in a domain.

APIPA

Automatic Private IP Addressing — the 169.254.0.0/16 address a host self-assigns when no DHCP server responds.

BIOS/UEFI

Motherboard firmware that initializes hardware at power-on and starts the boot process; UEFI is the modern version with Secure Boot and GPT support.

BitLocker

Windows full-disk encryption (Pro and higher) that uses the TPM to protect data if a device is lost or stolen.

Change management

A documented process to request, assess, approve, implement, and review changes safely.

CIA triad

The three goals of security: Confidentiality, Integrity, and Availability.

CPU

Central Processing Unit — the processor that executes instructions; mounts in an LGA or PGA socket.

DDR5

The current generation of system RAM — higher bandwidth and lower voltage (1.1V) than DDR4; the modules are keyed differently and are not interchangeable.

DHCP

Dynamic Host Configuration Protocol — automatically assigns IP address, mask, gateway, and DNS to clients (ports 67/68).

DISM

Deployment Image Servicing and Management — repairs the Windows component store/image.

DNS

Domain Name System — resolves hostnames to IP addresses (port 53).

ECC RAM

Error-Correcting Code memory that detects and corrects single-bit errors; used in servers and workstations where data integrity matters.

ESD

Electrostatic discharge — static that can destroy components; controlled with antistatic straps and mats.

exFAT

A file system for flash media that removes FAT32's 4 GB file-size limit; good cross-platform.

FAT32

An older, widely compatible file system limited to 4 GB maximum file size and no permissions.

Group Policy

Centralized Windows configuration of computers and users, applied in a domain or locally (Pro+).

Hypervisor

Software that creates and runs virtual machines; Type 1 runs on bare metal, Type 2 on a host OS.

IaaS

Infrastructure as a Service — rent raw compute, storage, and networking; you manage the OS and apps.

IP address

A logical address identifying a device on a network; IPv4 is 32-bit (dotted decimal), IPv6 is 128-bit.

Least privilege

Granting users only the minimum access needed for their job to limit damage.

M.2

A compact internal expansion form factor for SSDs (SATA or NVMe), Wi-Fi, and cellular cards.

Malware

Malicious software — viruses, worms, Trojans, ransomware, spyware, rootkits, and cryptominers.

MFA

Multifactor authentication — requires two or more factors (know, have, are) to verify identity.

NAT

Network Address Translation — lets many private IPs share one public IP and hides the internal network.

NTFS

The modern Windows file system with permissions, encryption, journaling, and large-file support.

NVMe

Non-Volatile Memory Express — a storage interface that runs SSDs over PCIe lanes for multi-gigabyte-per-second speeds.

PaaS

Platform as a Service — a managed platform to build and run apps without managing servers.

PCIe

PCI Express — the high-speed expansion bus for GPUs, NVMe SSDs, and add-in cards (x1, x4, x8, x16 lanes).

Phishing

A social-engineering attack using fraudulent messages to steal credentials or deliver malware.

PoE

Power over Ethernet — delivers power and data over one Ethernet cable to APs, cameras, and phones.

POST

Power-On Self-Test — the firmware hardware check at startup; failures are signaled by beep codes or diagnostic LEDs.

PSU

Power Supply Unit — converts AC wall power to the DC voltages (+3.3V, +5V, +12V) the PC needs.

RAID

Redundant Array of Independent Disks — combining multiple drives for performance, redundancy, or both (levels 0, 1, 5, 10).

RAM

Random Access Memory — fast, volatile system memory that holds running programs and data; cleared when power is lost.

Ransomware

Malware that encrypts files and demands payment for the key; defended by offline backups.

Rootkit

Stealthy, privileged malware that hides itself and is very hard to detect or remove.

Router

A Layer-3 device that forwards packets between different networks using IP addresses.

SaaS

Software as a Service — ready-to-use applications over the internet; the provider manages everything.

Safe Mode

A Windows startup mode with minimal drivers/services used to troubleshoot drivers, updates, and malware.

SATA

Serial ATA — the common interface for hard drives and entry-level SSDs (about 600 MB/s).

SDS

Safety Data Sheet — documents safe handling, storage, and disposal of chemicals and components.

sfc /scannow

System File Checker — scans and repairs corrupted Windows system files.

Social engineering

Manipulating people (phishing, tailgating, impersonation) to gain access or information.

SSD

Solid-State Drive — storage using flash memory with no moving parts; far faster and more durable than a hard disk drive.

Subnet mask

Separates the network and host portions of an IP address, defining which addresses share a local network.

Switch

A Layer-2 device that forwards frames within a LAN using MAC addresses.

System Restore

Rolls Windows system files and settings back to an earlier restore point without touching personal files.

TCP

Transmission Control Protocol — connection-oriented, reliable, ordered delivery (web, email, file transfer).

TPM

Trusted Platform Module — a chip that securely stores cryptographic keys; required for BitLocker and Windows 11.

Trojan

Malware disguised as legitimate software that delivers a hidden payload or backdoor when run.

UAC

User Account Control — prompts for elevation before system changes, supporting least privilege.

UDP

User Datagram Protocol — connectionless and fast with no delivery guarantees (streaming, VoIP, DNS).

UPS

Uninterruptible Power Supply — battery backup that allows a clean shutdown during a power outage.

Virtual machine

A software-based computer running its own OS on shared host hardware via a hypervisor.

Virus

Malware that attaches to a file/program and spreads when a user runs the infected host.

VLAN

Virtual LAN — logically segments a switch into separate broadcast domains for isolation.

VPN

Virtual Private Network — encrypts traffic over an untrusted network for secure remote access.

Worm

Self-replicating malware that spreads across networks without user action.

WPA3

The current Wi-Fi security standard; stronger than WPA2 and far stronger than the broken WEP.

CompTIA A+ Study Guide FAQ

References

1. 1.CompTIA. “A+ Core 1 and Core 2 (V15) Certification.” comptia.org. ↑
2. 2.CompTIA. “A+ 220-1201 (Core 1) Exam Objectives, V15.” comptia.org. ↑
3. 3.CompTIA. “A+ 220-1202 (Core 2) Exam Objectives, V15.” comptia.org. ↑
4. 4.Microsoft Learn. “NTFS overview.” learn.microsoft.com. ↑
5. 5.Microsoft Learn. “BitLocker overview.” learn.microsoft.com. ↑
6. 6.Microsoft Learn. “User Account Control overview.” learn.microsoft.com. ↑
7. 7.Microsoft Learn. “Use the System File Checker tool.” learn.microsoft.com. ↑
8. 8.National Institute of Standards and Technology (NIST). “Computer Security Resource Center Glossary.” csrc.nist.gov. ↑
9. 101.Microsoft Learn. “Start your PC in Safe Mode in Windows.” support.microsoft.com, accessed 19 June 2026. ↑
10. 102.National Institute of Standards and Technology (NIST). “Confidentiality (CIA) — Glossary.” csrc.nist.gov, accessed 19 June 2026. ↑
11. 103.National Institute of Standards and Technology (NIST). “Phishing — Glossary.” csrc.nist.gov, accessed 19 June 2026. ↑
12. 104.National Institute of Standards and Technology (NIST). “Multi-factor authentication — Glossary.” csrc.nist.gov, accessed 19 June 2026. ↑
13. 105.National Institute of Standards and Technology (NIST). “Ransomware — Glossary.” csrc.nist.gov, accessed 19 June 2026. ↑

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