|Q: Has Windows operating system a built-in antivirus software?|
|A: Yes, if your computer is running Windows 8 or later, you can use the built-in Windows Defender to help you get rid of viruses, spyware, or other malware.|
If your computer is running Windows 7 or Windows Vista, Windows Defender only removes spyware. To get rid of viruses and other malware, including spyware, on Windows 7 or Windows Vista, download Microsoft Security Essentials from the following URL:
https://support.microsoft.com/en-us/help/14210/security-essentials-download for free, and then install it.
In both cases you have to enable automatic Windows Update.