Microsoft Defender antivirus software, which is integrated into Windows 10, monitors your system in real-time but also allows manual scanning. However, the options include not only Quick Scan, Full Scan, and Custom Scan, but also Windows Defender Offline Scan, a special scan mode where Windows 10 is scanned immediately after booting in the recovery environment.
To start it, press the Windows+I hotkey and click on the Windows Update and Security / Open Windows Security command in the Control Panel. Select the Virus and Threat Protection / Scan Settings button, select Windows Defender Offline Scan and click Scan Now / Scan to start the scan. Windows 10 will then shut down and start in the recovery environment to continue scanning for viruses without unnecessary software and other components, in the cleanest possible environment. Once the process is complete, the computer will then automatically reboot and you’ll be back to your normal system – hopefully without any malware.