How to Run a Virus Scan With Windows Defender

Windows Defender is a free antivirus program built into every Windows computer — here's how to run a scan and check your computer is protected.

In this guide (5 steps):

1.Open Windows Security
2.Run a Quick Scan
3.Run a Full Scan for peace of mind
4.Make sure real-time protection is turned on
5.Keep Windows updated for the best protection

Open Windows Security

~26s

Click the Start button (the Windows logo at the bottom of the screen) and type "Windows Security." Open the Windows Security app. The main screen shows a dashboard with colored shields for different protection areas. Green checkmarks mean everything is working. A yellow or red warning means something needs attention.

Quick Tip

You can also find Windows Security by clicking the small shield icon in the system tray — the cluster of small icons at the bottom right of your screen near the clock.

Run a Quick Scan

~28s

Click "Virus & threat protection." Under "Current threats," click "Quick scan." Windows Defender scans the areas of your computer most likely to have viruses. A quick scan usually takes 2-5 minutes. When it finishes, you'll see either "No current threats" (your computer is clean) or a list of any items found. Quick scans are good for routine checks.

Quick Tip

Run a Quick Scan about once a month even if you haven't noticed any problems. Windows Defender also scans files automatically in real time as you download and use them.

Run a Full Scan for peace of mind

~21s

For a thorough check — especially if your computer has been behaving strangely — click "Virus & threat protection" → "Scan options" → check "Full scan" → click "Scan now." A full scan checks every file on your computer and typically takes 30 minutes to an hour. Your computer is usable during the scan, but it will run more slowly.

Make sure real-time protection is turned on

~27s

Click "Virus & threat protection" → scroll down to "Virus & threat protection settings" → click "Manage settings." Make sure "Real-time protection" is turned ON (toggle should be blue/on). Real-time protection monitors everything your computer does and blocks threats automatically — this should always be on.

Warning

If you have a third-party antivirus program installed (like McAfee or Norton), Windows Defender typically turns off its real-time protection automatically to avoid conflicts. This is expected behavior — you're protected by the other program instead.

Keep Windows updated for the best protection

~17s

Windows Defender's virus definitions update automatically through Windows Update. To check that your updates are current: click StartSettingsWindows Update → click "Check for updates." Install any available updates. Virus definition updates happen frequently (often daily) and are small downloads that don't require a restart.

You Did It!

You've completed: How to Run a Virus Scan With Windows Defender

Need more help? Get Expert Help from a TekSure Tech

Windows Defender — now called Windows Security — is a free, built-in antivirus and security program that comes with every Windows computer. You do not need to buy a separate antivirus program; Windows Defender provides solid protection on its own. Here's how to check that it's running and do a virus scan.

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