How to Run a Virus Scan with Windows Defender
Windows Defender is your PC's built-in antivirus — here's how to run a manual scan and check your protection status.
Open Windows Security
~15sCheck your protection status
~24sQuick Tip
If you see a message that protection is off, click the "Turn on" button to re-enable it. Defender should always be running unless you have a separate antivirus program installed.
Run a Quick Scan
~16sRun a Full Scan for a thorough check
~18sReview any threats found
~25sWarning
If Defender finds a threat it cannot handle automatically, it will ask you to decide what to do. "Remove" is the safest choice for anything flagged as a virus or malware.
Check that automatic updates are on
~17sYou Did It!
You've completed: How to Run a Virus Scan with Windows Defender
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Windows Defender — now officially called Microsoft Defender Antivirus — is a free antivirus and security program built into every Windows 10 and Windows 11 computer. You do not need to buy or download anything extra. It runs automatically in the background and scans new files as they arrive, but you can also run a manual scan at any time to check your computer for threats.
Many Windows users are not aware that Defender is running because it works quietly in the background without interrupting you. It updates its list of known viruses and malware every day (as long as your PC has internet access), which is how it stays current against new threats.
To check your protection status or run a manual scan, click the Start button (the Windows icon in the lower left of your screen), type "Windows Security," and press Enter. This opens the Windows Security dashboard — a central hub for all your computer's protection tools.
On the main dashboard, you will see colored circles for different protection categories. Green checkmarks mean everything is working normally. A yellow exclamation mark means something needs your attention. A red X means a protection feature is off or there is a threat to address.
To run a scan, click "Virus & threat protection." This screen shows the date of your last scan and lets you choose between scan types. A Quick Scan takes a few minutes and checks the areas where threats are most commonly found. A Full Scan takes longer (often 30 to 60 minutes on a typical PC) but checks every file on your computer. Run a Quick Scan first — if any problems are found, Defender will prompt you about next steps.
When Defender finds a threat, it moves the suspicious file to a quarantine area automatically. You can review quarantined items under "Protection History." For most users, the default action (quarantine) is the right choice, and Defender handles it without needing your involvement.
If you have a third-party antivirus program installed — like Norton, McAfee, or Bitdefender — Windows will typically disable Defender automatically to avoid conflicts. You do not need both running at the same time.
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