How To Run A Full System Scan On Windows 11: A Step-by-Step Guide

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Edgar Nicov

How-To

5 min. read

Published on October 22, 2025

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Keeping your Windows 11 system running smoothly requires regular maintenance, and one of the most important aspects of that is performing system scans. These scans help identify and eliminate malware, repair corrupted files, and ensure overall system stability. This guide provides a comprehensive, step-by-step approach to running a full system scan on your Windows 11 computer.

Whether you’re a seasoned tech enthusiast or a new Windows 11 user, understanding how to initiate and interpret system scans is crucial for maintaining a healthy and secure computing environment. This article will walk you through various methods, including using Windows Security, Command Prompt, and third-party antivirus solutions, to ensure every nook and cranny of your system is thoroughly checked.

What Are The Steps To Scan Your Windows 11 System?

Using Windows Security for a Full System Scan

Windows Security, formerly known as Windows Defender, is the built-in antivirus and security suite in Windows 11. It offers comprehensive protection and includes a full system scan option.

Open Windows Security. You can find it by searching for “Windows Security” in the Start menu.
Click on “Virus & threat protection”.
Under “Current threats,” click on “Scan options”.
Select “Full scan” and then click “Scan now”. This will initiate a thorough scan of your entire system.
Wait for the scan to complete. The duration will depend on the size of your hard drive and the number of files on your system.
Review the scan results. If any threats are found, follow the on-screen instructions to remove or quarantine them.

Running a Scan from Command Prompt

Command Prompt provides a more technical way to initiate a system scan using the built-in Microsoft Defender Antivirus.

Open Command Prompt as an administrator. Search for “Command Prompt” in the Start menu, right-click on it, and select “Run as administrator.”
Type the following command and press Enter: "%ProgramFiles%\Windows Defender\MpCmdRun.exe" -Scan -ScanType 2
The scan will begin immediately. Command Prompt will display progress and any detected threats.
Once the scan is complete, review the results in the Command Prompt window.

Utilizing Third-Party Antivirus Software

If you prefer using a third-party antivirus solution, the process for running a full system scan will vary depending on the software you have installed. However, the general steps are similar.

Open your antivirus software.
Look for a “Scan” or “System Scan” option.
Select the option for a “Full Scan” or “Deep Scan”.
Initiate the scan and wait for it to complete.
Review the scan results and take appropriate action on any detected threats.

Scheduling Regular Scans

To ensure continuous protection, schedule regular system scans.

Open Task Scheduler. Search for “Task Scheduler” in the Start menu.
Click “Create Basic Task” in the right-hand pane.
Give the task a name (e.g., “Windows Defender Full Scan”) and click “Next”.
Choose a trigger for the task (e.g., “Daily,” “Weekly,” or “Monthly”) and click “Next”.
Set the specific day and time for the scan to run and click “Next”.
Select “Start a program” and click “Next”.
In the “Program/script” field, enter: "%ProgramFiles%\Windows Defender\MpCmdRun.exe"
In the “Add arguments” field, enter: -Scan -ScanType 2
Click “Next” and then “Finish”.

Tips for Effective System Scans

Update your antivirus software regularly to ensure it has the latest virus definitions.
Disconnect from the internet during a scan to prevent malware from communicating with external servers.
Close unnecessary programs to free up system resources and speed up the scan.
Run scans during off-peak hours to minimize performance impact.
Consider using a bootable antivirus rescue disk for deep infections that prevent Windows from starting.

System Security: A Proactive Approach

Regularly scanning your Windows 11 system is a crucial step in maintaining its security and performance. By following the methods outlined above, you can proactively protect your computer from malware and ensure a smooth and reliable computing experience.

FAQ

How often should I run a full system scan? It’s recommended to run a full system scan at least once a week, or more frequently if you suspect a malware infection.

Will a full system scan slow down my computer? Yes, a full system scan can temporarily slow down your computer, especially during the scan process. It’s best to run scans during off-peak hours.

What should I do if a scan detects a threat? Follow the on-screen instructions provided by your antivirus software to remove or quarantine the threat.

Can a full system scan fix corrupted files? While a full system scan primarily focuses on detecting malware, some antivirus programs can also repair corrupted system files.

Is Windows Security enough to protect my computer, or do I need a third-party antivirus? Windows Security provides a good level of protection, but a third-party antivirus may offer more advanced features and detection capabilities. Consider your specific needs and risk tolerance when making this decision.