Why You Need More Than One Security Tool
No single security tool catches every threat. Antivirus programs are excellent for known malware signatures, but they can miss newer threats, rootkits, adware, or PUPs (Potentially Unwanted Programs). Using a layered approach — a combination of specialised tools — gives you much more comprehensive protection.
The good news: many of the best security tools are free. Here's what they are, what they do, and when you should reach for each one.
Core Security Tools Every Windows User Should Know
1. Windows Defender (Microsoft Defender Antivirus)
What it does: Real-time protection against viruses, ransomware, spyware, and other malware. Built into Windows 10 and 11.
Strengths: Always up to date, deeply integrated with the OS, zero cost, and no installation required. Independent testing labs consistently rank it as effective for everyday protection.
Limitations: Less effective against newer zero-day threats without supplementary tools. May miss adware and PUPs by design.
When to use it: As your always-on, baseline protection layer.
2. Malwarebytes Free
What it does: On-demand scanning for malware, adware, PUPs, and browser hijackers. The free version does not include real-time protection.
Strengths: Excellent detection of adware and PUPs that traditional antivirus tools ignore. Fast scan times. Pairs well with Windows Defender.
Limitations: Free version requires manual scans — it won't actively block threats in real time.
When to use it: For periodic manual scans, or when you suspect an infection that your primary antivirus missed.
3. Malwarebytes AdwCleaner
What it does: Specifically targets adware, browser hijackers, unwanted toolbars, and PUPs.
Strengths: Lightweight, fast, and highly effective at cleaning browser junk. Free with no ongoing subscription.
Limitations: Not a full antivirus. Designed for a single purpose.
When to use it: When your browser is behaving strangely — redirects, new toolbars, unwanted extensions.
4. HitmanPro (30-day free trial)
What it does: A "second opinion" scanner that uses multiple cloud-based engines to detect threats. Particularly effective against persistent and stealthy malware.
Strengths: Does not install anything on your system — runs entirely from a single executable. Excellent for checking if a system is clean after manual removal.
Limitations: Free for 30 days; paid after that. Not suitable as a long-term primary scanner.
When to use it: After an infection, to verify your system is clean.
5. Kaspersky TDSSKiller
What it does: Specifically scans for and removes rootkits — a type of malware that hides deep in the operating system and is invisible to most scanners.
Strengths: Free, portable (runs without installation), and targeted for a type of threat most tools miss.
Limitations: Narrow scope — not a general malware scanner.
When to use it: If you suspect a rootkit infection, or as part of a thorough post-infection cleanup.
6. Autoruns (Microsoft Sysinternals)
What it does: Shows every program, service, and driver configured to run automatically on Windows — far more comprehensive than Task Manager.
Strengths: Completely free from Microsoft. Invaluable for identifying malware that has embedded itself into startup processes.
Limitations: Technical — not beginner-friendly. Requires care to avoid disabling legitimate system components.
When to use it: When investigating persistent malware or unexplained startup behaviour.
Quick Comparison
| Tool | Best For | Real-Time? | Free? |
|---|---|---|---|
| Windows Defender | Everyday protection | Yes | Yes |
| Malwarebytes Free | Malware & PUP scanning | No | Yes |
| AdwCleaner | Adware & browser hijackers | No | Yes |
| HitmanPro | Second-opinion scanning | No | Trial only |
| TDSSKiller | Rootkit detection | No | Yes |
| Autoruns | Startup investigation | No | Yes |
A Sensible Toolkit Strategy
For most users, a solid baseline is: Windows Defender running continuously, with a monthly manual scan using Malwarebytes Free. If you notice browser issues, run AdwCleaner. After a serious infection, follow up with HitmanPro and TDSSKiller to verify the all-clear.
This layered approach costs nothing and covers the full spectrum of common threats.