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How to Scan for Viruses on Windows 10/11 Full System Using the Built-in Program You Already Have
Learn how to scan for viruses and malware on a Windows 10/11 computer with a full system scan (Full Scan) using the built-in Windows Security program, from the steps of updating the database to handling detected threats, for the safety of your data.
Feeling like your computer is unusually slow, or worried that you might have accidentally clicked a link and installed unwanted software? This article will guide you on how to use tools already available on every Windows computer to scan for threats thoroughly in every corner, so you can use your computer with greater peace of mind.
Understand before fixing
In Windows 10 and 11, there is a security program called Windows Security (or what many people are more familiar with as the former name Windows Defender) pre-installed from the factory. It has capabilities comparable to general antivirus programs. One of the most important functions is to scan for harmful files or malware.
Scanning has several levels, but the commonly used ones are:
- Quick Scan: This is a scan of important areas where malware often hides, such as in memory (RAM) and system startup folders. It takes a short time and is suitable for daily checks.
- Full Scan: This is a scan of all files and programs on every connected hard drive, similar to a thorough search of an entire house. It takes several hours, but it has a better chance of finding threats that are deeply hidden.
In this article, we will focus on performing a Full Scan, which is suitable for situations where you suspect that your computer might already be infected with a virus or want to conduct a yearly comprehensive check for assurance.
Before Starting
To ensure a smooth and safe scan, you should do a little preparation before starting:
1. Save your work and close programs: Save all open files and close unnecessary programs first to prevent data loss and to allow the scan to perform at full efficiency.
2. Plug in the power (for laptops): Full system scans consume a lot of power and take a long time. You should keep the charger plugged in throughout the scan to prevent the battery from running out halfway.
3. Connect to the Internet: This is extremely necessary for updating the virus database in the first step, so that the program can recognize new types of threats.
How to do it safely
Follow the steps below to scan your computer thoroughly and safely
Step 1: Update Virus Definitions
- WHAT: Command Windows Security to download information about the latest viruses and malware
- WHERE/HOW:
1. Click the Start button, then type Windows Security and press Enter
2. Select the Virus & threat protection menu
3. Under the Virus & threat protection updates heading, click on Protection updates
4. Click the Check for updates button and wait until the system notifies that Protection definitions are up to date
- WHY: Having an up-to-date database is like having the latest physical descriptions of criminals, allowing the program to detect new types of threats that have just emerged. If not updated, it may fail to detect new viruses.
- EXPECTED RESULT: The system will download a small update file and display a message confirming that the database is already the latest version
Step 2: Start a full system scan (Full Scan)
- WHAT: Command the program to start scanning all files on the computer
- WHERE/HOW:
1. In the Windows Security window, go back to the Virus & threat protection menu
2. Click on Scan options (may be under the Quick scan button)
3. Select the Full scan option
4. Click the Scan now button at the bottom
- WHY: To start a thorough scanning process, which will check every file, every folder, and every program running on your computer
- EXPECTED RESULT: The window will display the scan status along with a progress bar and the estimated time required, which may take from 1 to several hours, depending on the amount of data on the device.
Step 3: Let the scan complete
- WHAT: Do not interrupt or turn off the machine while the program is running
- WHERE/HOW: Let the computer run continuously. You may do light work, but the machine might slow down noticeably. The best approach is to schedule the scan to run during lunch break or at night before leaving work.
- WHY: Stopping the scan midway will result in an incomplete check and may miss dangerous files that have not yet been scanned.
- EXPECTED RESULT: The progress bar will run until it reaches 100%, and the screen will display the scan summary.
Step 4: Check the results and manage threats
- WHAT: View the scan report results and decide how to handle suspicious files according to the program's recommendations
- WHERE/HOW:
- If no abnormalities are found, a message will indicate No current threats
- If a threat is detected, the program will display a list of those files, along with buttons to take actions, such as Start actions
- WHY: Detection is only halfway. You need to instruct the program to handle those files. Normally, Windows Security will automatically choose the most appropriate action, such as quarantine to stop the file from running, or remove it entirely.
- EXPECTED RESULT: After clicking Start actions, the status will return to No current threats, indicating that your device is safe from detected threats.
Check Results
1. View protection history: Go to Windows Security > Virus & threat protection > Protection history. You will see the record of the most recent scans and the list of threats that have been handled.
2. Observe the operation of the machine: After restarting the machine once, try to observe whether any abnormal symptoms, such as the machine being slow, freezing, or unusual windows popping up, disappear or not.
3. Try Quick Scan again: The next day, try running Quick Scan again. The results should show that no threats are found.
If not yet recovered
If performing a Full Scan does not improve the situation, it is possible that the malware is highly sophisticated and can hide from normal scans. Try using Microsoft Defender Offline scan, which is another option on the Scan options page. This type of scan will restart the computer and run before Windows fully loads, allowing deeply embedded malware no chance to operate and making it easier to detect.
However, if the problem persists after trying every method, it may not be a virus issue, but could be due to a problem with the driver, software, or hardware. If it is a company computer, you should notify the IT Support immediately so that experts can check it further with advanced tools.
Summary
A full system virus scan (Full Scan) with Windows Security is a powerful and easy-to-use free tool that helps ensure your computer is clean and safe. Doing it regularly, along with practicing safe online behavior, can greatly reduce the risk of cyber threats.