NOTE: Before performing any significant repairs, back up your computer's hard drive.
Windows Defender Antivirus regularly scans your device to help keep it safe. We try to do this while you’re not using your device so it doesn’t interfere with your work. You can also schedule Windows Defender Antivirus to scan at a time and frequency that you choose.
1. Search for and open Schedule tasks.
2. In the left pane, expand Task Scheduler Library > Microsoft > Windows, and then scroll down and select the Windows Defender folder.
3. In the top center pane, double-click Windows Defender Scheduled Scan.
4. In the Windows Defender Scheduled Scan Properties window, select the Triggers tab, go to the bottom of the window, and then select New.
5. Specify how often you want scans to run and when you’d like them to start.