How to run Microsoft Defender full virus scan on Windows 11

To perform a full virus scan with the Microsoft Defender Antivirus, open Windows Security > Virus & threat protection > Scan options, choose “Full,” and click “Scan now.”
You can also use Command Prompt and PowerShell commands to run a full virus scan on your computer.

On Windows 11, Microsoft Defender Antivirus runs continuously in the background to monitor the system and protect your device from a wide range of threats, including viruses, ransomware, spyware, rootkits, and other forms of malware. The built-in security engine uses real-time protection and cloud-based intelligence to detect suspicious activity and automatically remove malicious software before it can damage the system.

Even though the antivirus protection is always active, there are situations where running a manual scan is the best way to confirm the system is clean. For example, if the computer suddenly becomes slow or unresponsive, if apps behave unexpectedly, or if you suspect that a malicious file may have bypassed real-time protection, performing a deeper scan can help identify hidden threats.

Windows 11 includes several scanning options that allow you to check the system at different levels. From the Windows Security app or through command-line tools like Command Prompt and PowerShell, you can initiate three types of scans, including a quick scan for common threat locations, a custom scan to check specific folders or drives, or a full scan that examines the entire system to ensure no malware is present.

In this guide, I will teach you how to perform a complete virus scan using Windows 11’s built-in anti-malware solution.

Run a full virus scan on Windows 11
Run a full virus scan from Command Prompt
Run a full virus scan from PowerShell

Run a full virus scan on Windows 11

To perform a full virus scan on Windows 11, follow these steps:

Open Start on Windows 11.
Search for Windows Security and click the top result to open the app.
Click on Virus & threat protection.
Click on Scan options under the “Current threats” section.
Select the Full scan option to check the entire system for viruses and any other type of malware.
Click the Scan now button.

Once you complete the steps, Microsoft Defender Antivirus will scan the computer for viruses and other types of malware. If anything is detected, the antivirus automatically removes (or quarantines) the threats.

Run a full virus scan from Command Prompt

To run a Microsoft Defender Antivirus scan with commands, follow these steps:

Open Start.
Search for Command Prompt, right-click the top result, and select the Run as administrator option.
Type the following command to locate the latest version of Microsoft Defender Antivirus installation and press Enter:
```
cd C:\ProgramData\Microsoft\Windows Defender\Platform\4*
```
Type the following command to run a full virus scan and press Enter:
```
mpcmdrun -scan -scantype 2
```

After you complete the steps, Microsoft Defender will scan, detect, and remove any malware on the computer. You will notice the “Start scanning” messages as you execute the command. Once the scan is complete, the “Scan finished” message will return on the screen.

Run a full virus scan from PowerShell

To start a full virus scan with PowerShell, follow these steps:

Open Start.
Search for PowerShell, right-click the top result, and select the Run as administrator option.
Type the following command to start a full malware scan and press Enter:
```
start-mpscan -scantype fullscan
```

Once you complete the steps, the antivirus will perform a full scan on Windows 11 to remove any malware.

Although you cannot run a full virus scan with the Microsoft Defender Antivirus if you use a third-party security solution, you can still enable and use the periodic scanning feature.

FAQs about full virus scan on Windows 11

Here’s a list of frequently asked questions (FAQs) and answers about

What is a full virus scan on Windows 11?

A full virus scan on Windows 11 checks the entire system for malware using Microsoft Defender Antivirus. Unlike a quick scan that targets common threat locations, a full scan analyzes all files, apps, and system areas to detect hidden threats such as viruses, ransomware, spyware, or rootkits.

What is the difference between quick scan, custom scan, and full scan in Microsoft Defender?

A quick scan checks common locations where malware typically hides. A custom scan targets specific folders or drives you choose. A full scan examines the entire system for threats. In Microsoft Defender Antivirus on Windows 11, the full scan provides the most thorough malware detection.

How do I run a full virus scan on Windows 11 using Windows Security?

To run a full virus scan on Windows 11, open Windows Security, select “Virus & threat protection,” click “Scan options,” choose “Full scan,” and click “Scan now.” Microsoft Defender Antivirus will then scan the entire device and automatically quarantine or remove detected threats.

How can I run a Microsoft Defender full scan using Command Prompt?

You can run a full scan using Command Prompt by launching the terminal as administrator, navigating to the Defender platform folder, and running the command mpcmdrun -scan -scantype 2. This command triggers Microsoft Defender Antivirus to scan the entire system on Windows 11.

Can I start a full Microsoft Defender scan with PowerShell?

Yes, you can start a full scan with PowerShell using the command start-mpscan -scantype fullscan. Running this command as an administrator instructs Microsoft Defender Antivirus to perform a complete malware scan across the system in Windows 11.

Why should I run a manual full virus scan if real-time protection is already enabled?

Running a manual full scan helps detect threats that may have bypassed real-time monitoring. If your computer becomes slow, apps behave unexpectedly, or you suspect malware, performing a complete scan with Microsoft Defender Antivirus on Windows 11 can help identify and remove hidden threats.

What happens if Microsoft Defender finds a virus during a full scan?

If Microsoft Defender Antivirus detects malware during a full scan on Windows 11, it automatically attempts to quarantine or remove the threat. Quarantined files are isolated so they cannot harm the system, and you can review them later from the Windows Security protection history to restore or permanently delete them.

Can I use my computer while Microsoft Defender is running a full scan?

Yes, you can continue using your device while Microsoft Defender Antivirus performs a full scan on Windows 11. However, you may notice reduced performance because the antivirus is actively analyzing files and processes. For best results, many users start full scans when the computer is idle or outside working hours.

How long does a full virus scan take on Windows 11?

A full virus scan on Windows 11 can take anywhere from 30 minutes to several hours, depending on the size of the hard drive, the number of files on the system, and the performance of the hardware.

Update March 13, 2026: This guide has been updated to ensure accuracy and reflect changes to the process.