For those suspecting their PC may harbor a virus, it’s reassuring to know that Windows comes equipped with a built-in virus checker. A thorough scan can be initiated with just a few clicks, following a structured approach to ensure maximum effectiveness.
1. Run a Windows Security Scan First
Begin by opening Windows Security. Navigate to Virus & threat protection, locate Current threats, and select Quick scan. This option provides the fastest built-in virus check available for Windows 10 and 11 when Microsoft Defender Antivirus is enabled. Once the scan is complete, you can review any findings by accessing Protection history.
2. Check Which Antivirus Is Active
- Open Windows Security, proceed to Virus & threat protection, select Who’s protecting me?, and then choose Manage providers.
- If Microsoft Defender Antivirus is active, continue with the Windows Security steps outlined below.
- In the event that a compatible non-Microsoft antivirus is installed, Microsoft Defender will automatically disable itself. To reactivate Defender, simply uninstall the non-Microsoft antivirus.
- To enable Defender’s real-time protection, navigate to Virus & threat protection, open Virus & threat protection settings, select Manage settings, and toggle Real-time protection to On.
3. Update Defender Before a Deeper Scan
Before conducting a virus scan, it is crucial to ensure that your security intelligence is up to date. Follow these steps:
- 1.Open Windows Security.
- 2.Go to Virus & threat protection.
- 3.Select Protection updates.
- 4.Click Check for updates.
After completing the update, remain in Windows Security to initiate the desired scan.
4. Run a Full Scan or Custom Scan
A full scan is advisable when a comprehensive check of your PC is required. To execute this, open Windows Security, navigate to Virus & threat protection, locate Current threats, select Scan options, choose Full scan, and then click Scan now.
If you prefer to check a specific location, opt for a custom scan. In Scan options, select Custom scan, click Scan now, and specify the file, folder, or drive you wish to examine. Alternatively, you can scan a single item directly from File Explorer by right-clicking the file or folder, selecting Show more options, and choosing Scan with Microsoft Defender.
5. Use Microsoft Defender Offline for Stubborn Malware
For persistent malware issues that resist standard scans, Microsoft Defender Offline provides a robust solution. Prior to initiating this scan, ensure that all work is saved, as Windows will restart during the process.
- Open Windows Security.
- Go to Virus & threat protection.
- Select Scan options.
- Choose Microsoft Defender Antivirus (offline scan).
- Click Scan now.
This scan operates in the Windows Recovery Environment and is only available when Microsoft Defender Antivirus is the active antivirus. After Windows restarts, you can view the results of the offline scan in Protection history.
6. Check Scan Results and Quarantined Threats
Upon completion of any scan, revisit Windows Security and select Protection history. This section provides insights into recent protection events, details on quarantined threats, and results from the Microsoft Defender Offline scan. Microsoft retains these records for two weeks, making it essential to check promptly after a scan concludes.
7. Use a Second-Opinion Virus Checker
- For a single suspicious file or link, consider using VirusTotal. Open VirusTotal in your browser, select File to upload a file, or choose URL to paste a link.
- VirusTotal assesses individual files, URLs, domains, and hashes using multiple engines, but it does not perform a comprehensive scan of your entire PC. Avoid uploading confidential files, as submissions are shared with VirusTotal’s security community. For sensitive files, search using their hash instead.
- For a one-time Microsoft scan, utilize Microsoft Safety Scanner. Download the appropriate version, run msert.exe, select the scan type, and review the results. Note that this tool expires ten days post-download and does not substitute for real-time antivirus protection.
- Another option from Microsoft is the Malicious Software Removal Tool. Download the x86 or x64 package, run it as an administrator on a supported Windows version, choose your scan type, and examine the results. This tool targets specific prevalent malware families and is not a replacement for a full antivirus application.
8. Skip Old Virus Checker Advice
It is advisable to disregard outdated recommendations that suggest using tools like the Chrome Cleanup Tool or Norton Power Eraser. Google has phased out Chrome Cleanup Tool scans since Chrome 111, and Norton has discontinued Norton Power Eraser as of April 30, 2026, rendering it ineffective. While Chrome still offers browser security checks, these do not encompass full PC virus scans. For browser security issues, navigate to More, access Settings, select Privacy and security, go to Safety Check, and follow the on-screen instructions.
Frequently Asked Questions
Can I scan one file without scanning the whole PC? Yes, simply right-click the file in File Explorer, select Show more options, and choose Scan with Microsoft Defender. Alternatively, you can upload a single file to VirusTotal for a multi-engine report.
Where do I find Microsoft Defender Offline scan results? You can find these results in Protection history within Windows Security, alongside other recent protection events.
Does Microsoft Safety Scanner replace antivirus protection? No, the Microsoft Safety Scanner is a manual, one-time scanner that expires ten days after download and does not provide real-time antivirus protection.
Can my work PC be scanned by IT? Yes, managed Windows devices can be scanned by administrators using Microsoft Defender for Endpoint or Microsoft Intune. Be sure to follow your organization’s IT protocols for work or school PCs.
