A new study conducted on May 9, 2018, by AV-Comparatives, ranked the most widely used antivirus programs on the market in terms of time to delay the performance of your system, for computers running Windows 10.
The test was performed on a Lenovo G50 powered by an Intel Core i3 chip, 4GB of RAM and a hard drive. The operating system was Windows 10, with the Fall Creators Update version and all the applications were installed with their default settings. 
AV-Comparatives has performed a number of tasks, including copying files, archiving and removing files, installing and removing applications, launching programs, downloading files, browsing web pages, and PCMark 10 application as reference.
The worst performance was recorded when testing Windows Defender from Microsoft, which comes pre-installed in Windows 10. Windows Defender caused a significant drop in performance when copying files and installing apps, with the smallest drop occurring during file downloads. Microsoft's security solution achieved a score of 96,7 on PCMark 10, which is not as good as Avira's 99,4 points, but not as bad as Quick Heal's 95,2 points.
Overall, Windows Defender solemnly finished in last place, while K7, ESET, Avast, AVG, Bitdefender and Kaspersky received the best results.
According to the research, the majority of antivirus solutions, barely affected performance when browsing websites or copying files, but the biggest slowdown was recorded when launching applications for the first time. Products of Tencent, Trend Micro, Emsisoft and VIPRE slow down systems when new applications are first run.
In a related note, AV-Comparatives states that "although we report the results for the first opening of an application as well as for subsequent openings, we consider subsequent openings more important, since this operation is performed several times by users".
Please note that this survey was conducted with a device low level, so the impact on performance can be significantly less in the case of a computer with newer hardware and SSD drives.
