Computer Security Software Considerations

by Billy J Long Guidance, PSA Articles

Article (PSA‑0023)

What Does “Enough” Security Look Like?

Every computer is different, but we can split the discussion into two groups:

  • Online computers – connected to a network or the internet.
  • Offline computers – never (or almost never) connected.

Online Computers – The Basics

1️⃣ Antivirus / Antimalware

  • Use **one** properly‑licensed, **up‑to‑date** product that offers:
    • Real‑time scanning – checks files as they are opened, created, or downloaded.
    • Scheduled scans – runs a full or selective scan at a set time (e.g., weekly).
    • On‑demand (manual) scans – you can scan a file or folder whenever you want.
  • Windows 10/11 include **Microsoft Defender Antivirus** at no extra cost. It meets the needs of most home users.
  • Third‑party suites (e.g., Norton, Bitdefender, Kaspersky) are fine, but they are often more expensive and can cause performance or compatibility issues if you try to run **more than one** AV product at the same time.

2️⃣ Firewall

  • Every Windows PC ships with **Windows Defender Firewall** – a software firewall that monitors inbound and outbound traffic.
  • A hardware firewall is typically your **router**; most home routers already provide basic NAT and packet‑filtering protection.
  • For the majority of users, the built‑in Windows firewall plus a router’s basic protection is **more than sufficient**. Buying a separate firewall product is rarely needed unless you run a small business with specific compliance requirements.

Offline (Never‑Online) Computers – When You Can Relax … a Bit

  • If the machine truly never connects to any network and never receives files from other computers, you can skip antivirus entirely.
  • However, if you ever plug in USB drives, external hard disks, or copy files from another (online) computer, you **should still run an antivirus scan** on that media before opening anything.
  • Even an offline system benefits from a firewall‑like rule set (e.g., disabling unnecessary services) to keep the attack surface minimal.

Why Adding More Security Tools Can Hurt More Than Help

  • RAM depletion – Each extra security program consumes memory. When RAM runs low, Windows uses the hard drive as “virtual memory,” which dramatically slows the entire system.
  • Software conflicts – Two real‑time scanners will often see each other as malicious activity, leading to constant alerts, false positives, or system freezes.
  • Potential corruption – One AV may quarantine the other’s core files, leaving the second product broken and difficult to uninstall.

Bottom Line for the Average User

For a computer that accesses the internet, a **single, up‑to‑date antivirus** (Microsoft Defender or a reputable third‑party product) plus the **built‑in Windows firewall** provides solid protection. Combine that with common‑sense habits (don’t click unknown links, keep software patched, back up data) and you’re well covered.

Need a Quick Security Check?

If you’re unsure about your current setup or would like a brief review, call PSA Computer Services at (707) 506‑6802.