Learn how to Turn On, Enable or Start Windows Defender manually on a Windows computer. If it doesn't help, you may need to troubleshoot the issue.

You can open Windows Security in Windows 11/10 using Search, CMD, Run, Explorer, PowerShell, Task Manager, etc. We have listed 10 ways!

You can now detect and block harmful third-party apps using Windows Defender Antivirus, and in this guide, we'll show you how to do it on Windows 10.