On Windows 10, Microsoft continues to include its free Windows Defender Antivirus software to scan, detect, and remove malware from your computer. However, many users choose to install third-party security software, such as Symantec’s Norton Antivirus, AVG, Avira, or McAfee and many others.
Although there are many suitable alternatives, there is no antivirus that will guarantee full protection from every malware, and to help with this issue starting, Windows Defender Antivirus ships a feature called “Periodic scanning.”
Periodic scanning will only be available on devices running a third-party antivirus, and when it’s enabled, Windows Defender Antivirus will remain disabled, but periodically will scan and remove any threats that the other antivirus software you installed may not have been able to detect.
How to enable Periodic scanning on Windows 10
Use these steps to enable “Periodic scanning” after adding a third-party antivirus on Windows 10:
Open Windows Security.
Click on Virus & threat protection.
Click the Windows Defender Antivirus options setting.
Turn on the Periodic scanning toggle switch.
Once Limited Periodic scanning is enabled on your computer, Windows 10 will use the Automatic Maintenance feature to make sure to run the scans on optimal times to minimize the impact on performance and battery life.
While Windows Defender Antivirus will detect and remove any malware it finds automatically, you will receive a notification of the new threat in Action Center, which you can click to open the antivirus software and take additional actions.
Windows Defender Antivirus Periodic scanning is only meant to provide an extra layer of security to make Windows 10 more secure when you use another antivirus solution already installed on your device.
Update June 3, 2019: This guide was originally published in 2016, and it’s been updated to reflect the new changes with the Windows Security app.