Get a second opinion from Windows Defender, when using a third-party antivirus, in Windows 10

We recommend that you install a security suite on your Windows 10 computer, that provides more features and better protection than the built-in Windows Defender Antivirus does. We appreciate products like Bitdefender, ESET, F-Secure, and so on. When you install a security suite, Windows Defender Antivirus gets disabled because it is not a good idea to simultaneously run two antivirus products that offer real-time protection. It is a recipe for failure, conflicts and performance issues. Luckily, in newer versions of Windows 10, you can keep your main antivirus turned on, and use Windows Defender Antivirus from time to time, for a second opinion, without causing any conflicts and issues between the two antivirus products. Here is how this works:

NOTE: To turn on this feature, you have to use Windows 10 logged with an account that has administrator permissions.

Step 1. Start Windows Security or Windows Defender Security Center

If you have Windows 10 April 2018 Update or older, you need to open Windows Defender Security Center. If you have Windows 10 October 2018, open Windows Security. They are the same app, with a different name and different features. If you do not know what version of Windows 10 you have, read this tutorial: What version, edition, and type of Windows 10 do I have installed?.

You can find Windows Security (Windows Defender Security Center) in the Start Menu, in the list of apps that start with the letter W.

The Windows Security shortcut from the Start Menu

You can also search for the word security and click or tap the Windows Security (Windows Defender Security Center) search result.

Searching for apps that include the word security

The Windows Security (Windows Defender Security Center) app looks similar to the screenshot below. In older versions of Windows 10, it has fewer options and settings, while in Windows 10 October 2018 update or newer, looks exactly like in the screenshot below.

The Windows Security app

Step 2. Enable periodic scanning in Windows Security (Windows Defender Security Center)

In the Windows Security (Windows Defender Security Center) app, click or tap "Virus & threat protection" on the left.

Then, in the middle of the window, expand the line that says: "Windows Defender Antivirus options."

Virus & threat protection options in Windows 10

A switch is shown for Periodic scanning. Set it to On.

Enabling Periodic scanning with Windows Defender Antivirus in Windows 10

A UAC prompt is shown, asking you to confirm this change. Press Yes and you are done.

An UAC prompt generated by Windows Security

From now on, Windows Defender Antivirus performs a quick scan, once in a while, to give you a second opinion about the state of security on your Windows 10 PC. That scan will not have a negative impact on the third-party antivirus that you have installed.

Another cool feature is that you can also immediately start a manual scan, without having to wait for Windows Defender Antivirus to decide when it is time to run a scan. Read the next step of this guide to learn how:

Step 3. Scan your Windows 10 PC with Windows Defender Antivirus, to get a second opinion

After you enable the periodic scanning feature, the Windows Security (Windows Defender Security Center) app changes, and displays more options in the "Virus & threat protection" section. You see Current threats and a Quick scan button.

Start a quick scan with Windows Defender Antivirus

When you press Quick scan, Windows Defender Antivirus makes a quick scan of your computer for malware and viruses and gives you a brief overview of its findings. However, it is a better idea to perform a full scan, for a more meaningful second opinion. To do that, under the Quick scan button click or tap the link that says: "Scan options" (in Windows 10 October 2018 Update) or "Run a new advanced scan" (in older versions of Windows 10).

Now you see a list of scanning options, including a full scan or a custom scan. Choose Full scan and press Scan now.

All the scanning options offered by Windows Defender Antivirus

Windows Defender Antivirus now performs a full computer scan for malware and viruses and gives you a more meaningful second opinion.

Do you like having the opportunity to get a second opinion from Windows Defender Antivirus?

Enabling the periodic scanning option is easy and something that you should do, for increased security, even if you already have a good antivirus product installed from a company other than Microsoft. You never know when your main antivirus might miss a threat, and it is identified by Windows Defender Antivirus instead. Enable this feature, use it, and let us know how well it works for you. Do you feel more secure when you have the options of getting a quick second opinion from Microsoft's antivirus? Comment below and let's discuss.