How to Remove Malware from Windows: Free Tools and Steps (2026)

In 2005 a painfully slow Windows 98 PC came to me for help. Spybot Search & Destroy found 66 problems and Ad-Aware found 361 more; after cleaning, My Computer opened in 5 seconds. Spyware was the culprit, not old hardware. Today Windows has strong built-in protection, but if you need to remove malware from Windows, these free steps work in 2026.

Quick answer: Open Windows Security > Virus & threat protection and run a Full scan, then a Microsoft Defender Offline scan to catch hidden malware. Get a second opinion with the free Malwarebytes scanner, uninstall unknown programs, reset your browsers and change important passwords from a clean device. If problems persist, back up your files and reset Windows.

Signs of malware

• Sudden slowness, high CPU or fan noise.
• Pop-ups, new toolbars or a changed browser homepage or search engine.
• Unknown programs starting with Windows.
• Security tools turned off, or accounts sending messages you didn’t write.

How to remove malware from Windows step by step

1. Disconnect from the internet if you suspect data theft.
2. Update Windows Security and run a Full scan.
3. Run Microsoft Defender Offline scan (Scan options), which restarts and scans before Windows loads.
4. Scan with the free Malwarebytes scanner as a second opinion.
5. Uninstall unfamiliar apps in Settings > Apps > Installed apps.
6. Reset browsers and remove unknown extensions.
7. Change passwords for email, banking and social accounts, ideally from another device, and turn on two-factor authentication.

When to reset Windows

If malware keeps returning, back up personal files (not programs) and use Settings > System > Recovery > Reset this PC, choosing to remove everything for a clean start.

Prevent future infections

• Keep Windows and apps updated.
• Download software only from official sites or the Microsoft Store.
• Don’t open unexpected attachments; learn to spot fakes with a phishing quiz.
• Use a standard (non-admin) account for daily use.

Still slow after cleaning? Try these ways to speed up Windows 11. On a Mac? See how to remove malware from a Mac.

FAQ

Is Windows Security enough?

For most people, yes, combined with safe habits and updates.

Are Spybot and Ad-Aware still useful?

They still exist, but Windows Security and Malwarebytes are the common choices in 2026.

Can malware survive a reset?

Rarely. A full reset with “remove everything” clears almost all malware.