This article will explain the distinctions among the various types of virus scans offered by Windows Security. Windows Defender, or Windows Security/Microsoft Defender Antivirus in Windows 11/10, is a built-in antivirus program developed by Microsoft. It allows you to monitor threats on your PC, scan your system for viruses, and protect your PC from malware and viruses using regularly updated security intelligence definitions.
Comparison: Windows Defender Offline Scan vs Full Scan vs Quick Scan
Windows Defender Antivirus provides four different types of scans for different scenarios. These scans include Quick Scan, Full Scan, Custom Scan, and Offline Scan.
All these virus scans are used to check for malicious software, viruses, and harmful files on your PC. However, they differ in their scanning methods. Let’s understand the differences among Windows Defender’s Quick Scan, Full Scan, Custom Scan, and Offline Scan.
| Scan Type | Definition | Duration | Recommended Usage |
| Quick Scan | Searches for malware in commonly known locations that may contain malware. It can detect and remove viruses in most cases. | Takes about 5 or 10 minutes to complete. | Recommended regular scan to keep your system protected from malware. |
| Full Scan | Scans the entire system, including all files, folders, and running programs, for viruses. | Can take hours to complete. | Use when you observe unusual behavior on your system and a quick scan does not suffice. |
| Custom Scan | Scans specific user-selected locations and folders for malicious software or files. | Takes a few minutes depending on the size of the folders and files being scanned. | Perform when you notice abnormal activity with specific files or folders. |
| Offline Scan | Scans the system for hidden malware, threats, rootkits, etc., in the Recovery environment. | Takes up to 15 minutes. | Run if Windows Security recommends performing an offline scan when rootkits are detected. |
Now, let’s discuss these four types of Windows Security scans in detail.
Quick Scan by Microsoft Defender Antivirus
The Quick Scan provided by Windows Defender/Windows Security is the most recommended scan for quickly finding and eliminating viruses, malware, and risks from your PC. It scans commonly known locations for viruses and malware, such as the Windows folder, Downloads folder, Registry keys, Windows startup folders, and more.
This virus scan protects your system from system and kernel-level malware and threats. As mentioned earlier, it is the recommended antivirus scan that is effective in most cases. It is selected by default in your Windows Security app. You can open the app and perform a quick scan immediately.
Read: Troubleshooting Quick Scan issues in Windows Defender.
Full Scan by Microsoft Defender Antivirus
Microsoft Defender Antivirus offers another type of scan, known as Full Scan, to help you protect your system from malware and viruses.
As the name suggests, Full Scan examines all files and programs present on hard drives, removable drives, and network drives. It initially performs a Quick Scan and then conducts a comprehensive scan of all files and running programs on your system using security intelligence definitions. It can even scan compressed files.
The time required for Full Scan depends on the amount of data to be scanned, and it may take hours or even days to complete. Therefore, it is not recommended to schedule this scan regularly. However, you can opt for a Full Scan occasionally to scan uncommon areas on your system for malware.
Read: Windows Security shows “No Security Providers” in Windows.
Custom Scan by Microsoft Defender Antivirus
Custom Scan is another type of scan that targets a specific location on your system. It is recommended when you suspect a folder or directory to be infected with malware. If you encounter issues with a particular location, you can run a Custom Scan. This scan takes less time compared to other scan types, and the duration depends on the size of the files being scanned.
Read: Best practices for using Windows Security for optimal protection.
Offline Scan by Microsoft Defender Antivirus
The fourth type of virus scan provided by Windows Defender is the Offline Scan. This scan helps you remove stubborn malware from your computer. It performs a quick scan in the Recovery environment. Essentially, Windows is rebooted, and a virus scan is performed at boot-time before the Windows OS is fully loaded. The Offline Scan typically takes about 15 minutes to complete.
Before running Microsoft Defender Offline, you need administrator rights. If you encounter a Stop error on a blue screen while running an offline scan, reboot your computer and attempt the scan again.
Read: Location of Windows Defender Offline scan logs.
How to Run Windows Defender Offline Scan, Full Scan, Quick Scan, or Custom Scan
You can initiate any of these scans from the Microsoft Defender Antivirus/Windows Security app on Windows 11. In Windows 10, the built-in security app is called Windows Defender Security Center. Follow these steps to run the scans:
Open the Windows Security app using the Windows search feature. Then, go to the Virus & threat protection tab in the left sidebar. Click on Scan options and choose the desired scan type. Finally, click on Scan now to start the scan. Allow Windows Security to complete the scan, and once finished, it will display the results.
Read: Performing a Windows Defender Offline Scan at boot time in Windows.
Should You Choose Quick Scan or Full Scan?
For finding and eliminating malware or viruses on your PC, it is recommended to use Microsoft Defender Antivirus’s Quick Scan. It is more efficient than a Full Scan because it specifically targets the locations where malicious software or infected files are commonly found. However, a Quick Scan may not detect all types of malware. In such cases, you can run a Full Scan to thoroughly scan all folders, files, and running programs on your system.
Read: Troubleshooting issues with Windows Defender Offline Scan.
Should You Use Windows Defender Offline Scan?
Run a Microsoft Defender Offline scan if Windows Security detects rootkits or other persistently harmful malware on your system. The app will recommend running an offline scan. Additionally, if you suspect that there is hidden, undetected malware on your PC, it is advisable to run the Microsoft Defender Offline scan.
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