Is your Windows 11 virus scan failing to run? This guide covers the most common causes and provides step-by-step fixes to restore Windows Security and protect your device.
“Hi, I use an HP laptop 14 with Windows 11. Whenever I try to download a file, it says ‘Couldn’t download - Virus scan failed.’ Any help is appreciated. I need to be able to download files!”
– HP Community
If you encounter download failed - virus scan failed on Windows 11, it’s mainly caused by:
🎯 Corrupted System Files: Critical files needed for scanning can be damaged by shutdowns, updates, or disk errors.
🎯 Disabled Core Services: Essential background services for Windows Security may be stopped or blocked.
🎯 Third-Party Antivirus Conflict: Incompletely removed security software can interfere and cause failures.
🎯 Malware Interference: Malicious programs can actively sabotage the antivirus engine to block scans.
🎯 Outdated System Components: Broken or incomplete Windows updates can prevent security features from working.
To build a strong protection layer for Windows 11, try this free Windows 11 backup software.
Before diving into complex repairs, it’s often possible to fix a Windows 11 virus scan failed error with a few simple checks. Here is a checklist:
✅ Restart Windows Security and Related Services
✅ Install Pending Windows 11 Updates
Go to Settings > Windows Update and install all available updates, including optional updates for security and Defender.
✅ Check System Time and Region
✅ Temporarily Disable Other Antivirus Programs
If you have third-party antivirus software installed, it may interfere with Windows Security. Temporarily disable or uninstall these programs to see if the scan runs correctly.
When basic checks don’t work, you can try the following advanced fixes. They apply to different browsers, such as virus scan failed on Chrome Windows 11.
1. Press Windows + S and type cmd. Right-click Command Prompt and select Run as administrator.
2. In the Command Prompt window, type sfc /scannow and press Enter.
3. Wait for the scan to reach 100%. Continue to the DISM scan by typing DISM /Online /Cleanup-Image /RestoreHealth and pressing Enter.
4. After DISM finishes, close Command Prompt and restart your PC. Check if the virus scan failed error disappears now.
1. Press Windows + I to open Settings.
2. Go to System → System components → Windows Security.
3. Click the three dots (⋯) next to it and choose Advanced options.
4. Scroll to the Reset section. Click Repair first.
5. If the issue remains, click Reset.
6. Restart your PC. After rebooting, open Windows Security and try running a virus scan again.
1. Press Windows + S, type Windows Security, and open it.
2. Click Virus & threat protection → Scan options.
3. Select Microsoft Defender Antivirus (offline scan) and click Scan now.
4. Windows will boot into a special recovery environment and begin scanning your system. Your PC will restart automatically when the scan is complete.
5. After logging back into Windows, open Windows Security → Protection history. Review whether threats were found and removed.
6. If threats are found, run a normal Full scan afterward to confirm your system is clean.
Note: This method is only workable if you have created a restore point before.
1. Press Win + R, type sysdm.cpl and press Enter.
2. In the System Properties window, select the System Protection tab. Then click System Restore.
3. The System Restore window will open. Click Next.
4. Select a restore point dated before the virus scan problem appeared and click Next.
5. Review your selection and click Finish.
6. Click Yes to confirm. Your computer will restart and begin restoring system files, settings, and Windows components.
7. After Windows loads, check if you can download a file without the virus scan failed error.
Fixing the Windows 11 virus scan failed error restores your system’s built-in protection—but true PC security goes beyond virus scanning. To build a strong protection layer for Windows 11, AOMEI Backupper Standard is an excellent free solution.
Flexible Backup Solutions: Choose to safeguard your entire Windows installation, specific files and folders, or a complete hard drive image—all on your own terms.
Scheduled & Automatic: Set up regular, hands-free backups to ensure your data protection is always up-to-date.
Effortless Disaster Recovery: Should your system fail, you can quickly restore your computer to an earlier date using a previously created backup image.
Bootable Recovery Media: Create a rescue USB, CD, or DVD to start and restore your system, even when Windows itself cannot boot.
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👉 To create a system image:
Click Backup > System Backup, select a backup destination, and click Start Backup.
👉 To create a recovery USB:
Click Tools > Create Bootable Media, select USB Boot Device as the destination, and click Create.
👉 To restore Windows 11:
Go to Home > Restore. Then select the system backup task you created earlier and follow the wizard to complete the process.
The Windows 11 virus scan failed error is more than just an inconvenience—it’s a warning sign that your system’s built-in protection is not working properly. By following the fixes in this guide, you can resolve most virus scan failures and bring Windows Security back to a healthy state.
However, relying on antivirus protection alone is not enough. To fully protect your Windows 11 PC, try AOMEI Backupper. It allows you to create regular system and file backups and restore Windows if malware causes damage. Download it on your PC now!