In the left side pane, expand Task Scheduler Library -> Microsoft > Windows, and then scroll down to select the Windows Defender folder.Hit the search box on your taskbar and type in Task Scheduler to launch the task scheduler app.How To Schedule A Scan In Microsoft Defender Antivirus In this guide, we will show you how to schedule a scan in Microsoft Defender Antivirus on your Windows 10 PC. You can also schedule Microsoft Defender Antivirus to scan at a time and frequency that you choose. While it protects you in real-time, you can manually scan the PC if you think it has virus, trojan or malware inside. It does this when you are not using your Windows PC, it has real-time scanning that protects throughout the usage, when you download a file, when you copy data, install software or programs, or insert a device via USB ports. It also keeps you safe from threats attacking your PC from the internet. Your built-in Microsoft Defender Antivirus regularly scans your PC to help keep fight the viruses and malware.