When switching antivirus software, your computer will be running and possibly connected to the internet without any protection.After a Windows Update, if the latest version of the tool is included, it’ll run automatically in the background.However, there are times when the tool is useful to run. If you are running such software, you never have to manually run the Windows Malicious Software Removal tool. You should also make sure Windows Firewall and Windows Defender are enabled. There are even free antivirus tools that work effectively at protecting your system, like Malwarebytes. You should always install and run an antivirus tool in the background. Never depend solely on regularly running the malicious software removal tool to protect your system. How You Should Use the Windows Malicious Software Removal Tool

Microsoft recommends using the Microsoft Safety Scanner for a complete, comprehensive scan for the latest malware threats.

Note: This tool only focuses on what Microsoft calls “prevalent malware families only”.

Microsoft malware removal tool