In testing, a full scan finished in just under an hour. Where many other antivirus products put a big Scan button front and center, Windows makes you work to even find the on-demand scan choices. Windows Defender focuses mainly on real-time protection. I'll go into detail about these features below. Clicking one of those icons (or its corresponding item in the left-rail menu) brings up a page for the selected security features. The main Windows Security screen displays large icons for virus protection and six additional feature collections. When you click the Defender icon in the notification area, it opens the full Windows Defender Security Center. Windows Defender differs from other free antivirus tools in that there's no installation required it's already present.
Windows Defender does a decent job, too, but the best competitors, including free ones, do even better. By making sure that every Windows installation has protection against malware, Microsoft helps contribute to a kind of herd immunity.
As soon as you install a third-party solution, it goes into suspended animation to avoid conflict. Windows Defender turns on to protect systems that have no other antivirus. In Windows 10, Windows Defender Security Center not only protects against all types of malware, but it also manages numerous other security features. Microsoft’s history of providing antivirus protection goes all the way back to DOS, but it’s never seemed to harm the third-party antivirus industry.