CompTIA A+ Core 2 (220-1102) Cheat Sheet 2026 — OS Commands, Security & Operational Procedures

Domain 1: Operating Systems (31%)

The largest domain. You must know Windows 10/11, macOS, and Linux installation, configuration, and management. Focus on command-line tools, Control Panel vs Settings, and OS architecture.

• Windows Editions: Home (no BitLocker, no Group Policy, no Remote Desktop host), Pro (BitLocker, GP, RDP host), Enterprise (DirectAccess, AppLocker), Education.
• Windows Architecture: Registry (HKLM, HKCU, HKCR, HKU, HKCC), System32, Program Files, AppData, Users folder.
• Control Panel vs Settings: Settings app (modern, Windows 10+). Control Panel (legacy, still needed for some tasks like Power Options, Network adapters).
• Disk Management: MBR (max 2 TB, 4 primary partitions) vs GPT (max 18 exabytes, 128 partitions). Dynamic vs Basic disks.
strong>File Systems: NTFS (Windows, permissions, encryption), FAT32 (legacy, max 4 GB file), exFAT (USB, cross-platform), ext4 (Linux), APFS (macOS).
• Windows Boot Process: POST → UEFI/BIOS → Bootloader (BOOTMGR) → Winload.exe → Kernel load → Logon.
• macOS: Based on Unix (Darwin). Disk Utility for disk management. Time Machine for backup. Keychain for passwords. .app bundles. Homebrew for package management.
• Linux Distributions: Ubuntu (apt, Debian-based), RHEL/CentOS (yum/dnf, Red Hat-based), Arch (pacman), Fedora. Desktop environments: GNOME, KDE, XFCE.
• Task Manager: Ctrl+Shift+Esc. Processes, Performance, Startup, Services tabs. End task, check resource usage.
li>Services: services.msc. Start/stop/restart services. Automatic vs Manual vs Disabled startup.
• MSConfig: Boot options, startup items, safe boot. System Configuration tool.
• Event Viewer: eventvwr.msc. Application, Security, Setup, System logs. Used for troubleshooting.

Domain 2: Security (25%)

Security covers malware, authentication, access control, and physical security. Know the difference between authentication and authorization, and common attack types.

• CIA Triad: Confidentiality (encryption), Integrity (hashing), Availability (redundancy/backups).
• AAA: Authentication (who are you?), Authorization (what can you access?), Accounting (what did you do?).
• Authentication Factors: Something you know (password), something you have (token/smart card), something you are (biometric). MFA = 2+ factors.
• Principle of Least Privilege: Give users only the access they need. No shared accounts.
• Malware Types: Virus (self-replicating, attaches to files), Worm (self-propagating, no host), Trojan (disguised as legitimate), Ransomware (encrypts data, demands payment), Spyware (covert monitoring), Rootkit (kernel-level, hard to detect).
• Phishing: Email-based social engineering. Spear phishing = targeted. Whaling = targets executives. Vishing = voice/phone. Smishing = SMS.
• Encryption: Symmetric (same key, AES, fast), Asymmetric (public/private key pair, RSA, slow), Hashing (SHA-256, one-way, integrity).
• BitLocker: Windows full-disk encryption. TPM chip required. Recovery key saved to AD or printed.
• Windows Defender: Built-in antivirus. Real-time protection, cloud-delivered, sandboxed execution.
• UAC (User Account Control): Prompts for permission when running as standard user. Reduces malware impact.
• Firewall: Host-based (Windows Defender Firewall), Network-based. Inbound/outbound rules. Stateful inspection.
• VPN: Encrypts traffic over public network. Site-to-site vs client-to-site. Protocols: IPsec, L2TP, OpenVPN, WireGuard.
• Physical Security: Mantrap (two-door system), Badge reader, Biometric lock, Cable lock (laptops), Locking racks.

Domain 3: Software Troubleshooting (22%)

Know the symptoms-to-cause mappings for common Windows, macOS, and mobile issues. The exam will describe a problem and ask for the solution.

• Blue Screen of Death (BSOD): Check Event Viewer, update drivers, run memory diagnostic (mdsched.exe), check for recent hardware/software changes, boot to Safe Mode.
• Boot Issues: BOOTMGR missing (rebuild BCD), Corrupt MBR (fixmbr), OS not found (check BIOS boot order, check drive), Infinite boot loop (disable restart on failure, check driver).
• Sluggish Performance: Check Task Manager, disable startup programs, check free disk space, run TRIM on SSD, check for malware, check Windows Update pending.
• App Crash: Check Event Viewer Application log, update app, reinstall app, run in compatibility mode, check DEP settings.
• Windows Update Failing: Run SFC /scannow, DISM /RestoreHealth, clear SoftwareDistribution folder, run Windows Update Troubleshooter.
• Disk Errors: chkdsk /f (fix), chkdsk /r (recover bad sectors), SFC /scannow (system file integrity), DISM /Online /Cleanup-Image /RestoreHealth.
• macOS Issues: Spinning beach ball = app busy/CPU. Boot to Recovery (Cmd+R). Disk Utility First Aid. Reset SMC / NVRAM. Safe Boot (hold Shift).
• Mobile Issues: App crash → force close, clear cache, reinstall. Wi-Fi issues → forget network, toggle airplane mode. Battery drain → check battery usage, background refresh.
• Printer Software: Print spooler stuck → restart Print Spooler service, clear queue. Wrong output → reinstall correct driver, check paper size settings.

Domain 4: Operational Procedures (22%)

Professionalism, safety, documentation, and change management. This domain is straightforward but easy to lose points on if you don't know the procedures.

• Documentation Types: Network topology diagram, Asset management (inventory), Knowledge base, Password policy, Acceptable Use Policy (AUP).
• Change Management: Request → Review → Approve → Implement → Document → Verify. Purpose: prevent unintended downtime.
• Incident Response: Identify → Isolate → Remediate → Document → Prevent.
• Standard Operating Procedures: Step-by-step guides for common IT tasks. Ensures consistency.
• Environmental Safety: ESD strap (ground yourself before touching components), Air filter (dust), Humidity control (30-50%), Temperature (60-75°F), Cable management.
• MSDS (SDS): Material Safety Data Sheet. Describes handling and disposal of hazardous materials (batteries, toner, cleaning chemicals).
• Proper Disposal: Batteries (recycling center, not regular trash), Toner cartridges (manufacturer recycling), CRT monitors (hazardous waste), Hard drives (physical destruction or secure wipe).
• Communication: Active listening, Avoid jargon with end users, Set expectations (timeline, next steps), Document and follow up. Empathy and professionalism.
• Remote Access Tools: RDP (Remote Desktop Protocol), VNC, TeamViewer, Screen Sharing (macOS). Always get user permission before connecting.
• Backup Strategies: Full (everything, slowest restore), Incremental (changes since last backup), Differential (changes since last full). 3-2-1 rule: 3 copies, 2 media, 1 offsite.

Windows Command Reference

Linux Command Reference

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