Think your PC has a virus? Windows already includes a virus checker, and the right scan only takes a few clicks.
Use the safest scan options in the right order: start with the fastest Windows Security check, then move to deeper scans and second-opinion tools.
1. Run a Windows Security Scan First
Open Windows Security, go to Virus & threat protection, find Current threats, then select Quick scan. This is the fastest built-in virus check for Windows 11 and Windows 10 when Microsoft Defender Antivirus is active.
Let the scan finish, then open Protection history to review anything Windows found.
2. Check Which Antivirus Is Active
- Open Windows Security, go to Virus & threat protection, select Who's protecting me?, then choose Manage providers.
- If Microsoft Defender Antivirus is active, use the Windows Security steps below.
- If a compatible non-Microsoft antivirus is installed, Microsoft Defender Antivirus automatically goes into disabled mode. Removing that non-Microsoft antivirus returns Defender to active mode.
- To turn Defender real-time protection on, go to Virus & threat protection, open Virus & threat protection settings, select Manage settings, then switch Real-time protection to On.
3. Update Defender Before a Deeper Scan
A virus scan needs current security intelligence.
- 1.Open Windows Security.
- 2.Go to Virus & threat protection.
- 3.Select Protection updates.
- 4.Click Check for updates.
After the update finishes, stay in Windows Security and run the scan you need.
4. Run a Full Scan or Custom Scan
Use a full scan when you want Windows to check the PC more thoroughly: open Windows Security, go to Virus & threat protection, find Current threats, select Scan options, choose Full scan, then click Scan now.
Use a custom scan when you only want to check one place. In Scan options, choose Custom scan, select Scan now, then choose the file, folder, or drive you want Windows to scan.
You can scan a single item from File Explorer too. Right-click the file or folder, choose Show more options, then select Scan with Microsoft Defender.
5. Use Microsoft Defender Offline for Stubborn Malware
Use Microsoft Defender Offline when malware keeps coming back or you need a scan outside normal Windows. Save your work first because Windows restarts during this scan.
- Open Windows Security.
- Go to Virus & threat protection.
- Select Scan options.
- Choose Microsoft Defender Antivirus (offline scan).
- Click Scan now.
Windows restarts and scans in the Windows Recovery Environment. This scan runs only when Microsoft Defender Antivirus is your active antivirus, so it will not appear if a non-Microsoft antivirus is your primary app, and it is not available on ARM-based PCs.
After Windows starts again, open Windows Security and go to Protection history to see the offline scan results.
6. Check Scan Results and Quarantined Threats
After any scan, open Windows Security and select Protection history. Windows shows recent protection events, quarantined threats, and Microsoft Defender Offline scan results there.
Microsoft says Protection history keeps events for two weeks, so check it right after the scan finishes.
7. Use a Second-Opinion Virus Checker
- For one suspicious file or link, use VirusTotal. Open VirusTotal in a browser, choose File and select Choose file, or choose URL and paste the link.
- VirusTotal checks individual files, URLs, domains, and hashes with multiple engines, but it does not scan your whole PC. Do not upload confidential or private files, because anything submitted to the public service is shared with VirusTotal's security community and partners. To check a sensitive file, search by its hash instead of uploading it.
- For a one-time Microsoft scan, use Microsoft Safety Scanner. Download the 32-bit or 64-bit version, open msert.exe, select the scan type, start the scan, and review the on-screen results. The tool expires 10 days after download and does not replace real-time antivirus.
- Microsoft's Malicious Software Removal Tool is another current Microsoft option. Download the x86 or x64 package from Microsoft, open the tool as an administrator on a supported Windows version, choose Quick Scan, Full Scan, or Customized scan, then review the results. It removes specific prevalent malware families and does not replace a full antivirus app.
8. Skip Old Virus Checker Advice
Do not use old guides that tell you to run Chrome Cleanup Tool or Norton Power Eraser.
Google removed Chrome Cleanup Tool scans starting in Chrome 111, and Norton says Norton Power Eraser was discontinued on April 30, 2026 and stopped working.
Chrome still has browser security checks, but they are not whole-PC virus scans. In Chrome, go to More, open Settings, select Privacy and security, go to Safety Check, select Go to Safety Check, then follow the on-screen instructions for browser security issues.
Frequently Asked Questions
Can I scan one file without scanning the whole PC?
Yes. In File Explorer, right-click the file, choose Show more options, then select Scan with Microsoft Defender. You can also upload a single file to VirusTotal for a multi-engine report.
Where do I find Microsoft Defender Offline scan results?
Open Windows Security and go to Protection history. Microsoft lists offline scan results there along with other recent protection events.
Does Microsoft Safety Scanner replace antivirus protection?
No. Microsoft Safety Scanner is a manual one-time scanner, expires 10 days after download, and does not replace real-time antivirus protection.
Can my work PC be scanned by IT?
Yes. Managed Windows devices can be scanned by administrators through Microsoft Defender for Endpoint or Microsoft Intune. Use your organization's IT process for a work or school PC.
