I was shocked when I saw the Windows defender won the Top Product in the latest AV-Test testing report, which was an underdog for quite a long time. AV-Test does an in-depth assessment of protection, performance, and usability: each facet’s full score is 6 points. Every software with 17.5 or 18 points can earn the title of Top Product. Windows Defender gets 6 of protection, 5.5 of performance, and 6 of usability. Whereas, is it necessarily the best choice?

Of course not. As we know, antivirus software can slow our computer down in virus degrees. We can refer to AV-Test’s Performance Test in April 2018, which includes file copying, archiving and unarchiving, installing/uninstalling applications, launching applications, downloading files, browsing websites.

Here are tested software and corresponding editions:
testing software

The higher the score, the greater the impact on the computer. According to the result, the Windows Defender marks 60 while K7 gets 90 of AVC Score. That is to say, the Windows built-in antivirus – Windows Defender effects biggest to the operating system.

Even with Windows Defender, if you care about performance, you’d better install third-party anti-virus software. After all, Windows Defender can only provide basic protection. Although it has excellent compatibility, you require professional software which provides all-around protection. If you wonder disable it to speed up your PC, you can take this article as an example: How to permanently disable Windows Defender.

Once you want to re-open Windows Defender, you may encounter such a problem: unable to start service. In this case, just walk through the quick down below to address the issue.

Step 1: Hit Window + R to invoke the Run window and input GPEDIT.MSC to execute the command.

Step 2: In the Local Policy Group Editor window, navigate to Computer Configuration > Administrative Templates > Windows Component > Windows Defender Antivirus. Go to the right pane and click on Turn off Windows Defender Antivirus.

local group policy editor

Step 3: Check on Disable on the pop-up window.
Note: Parts of third-party antivirus software would conflict with Windows Defender that the method above may not work as well.

turn off windows defender