


One of the common issues we have seen in the past is when there are multiple security software installed. Windows is designed to detect the presence of security software installed, and we often get to see the notification in the Action Center. One of the most common behaviors of Windows Defender is that if it detects a third-party antivirus software, then Windows Defender will shut itself off. Scan PC with portable antivirus softwareġ] Check if you have another security software installed.Check if you have another security software installed.If you are unable to start Windows Defender, then one of these suggestions is sure to help you:

If you face this issue, then this post may help you.Ĭan’t turn on Windows Defender in Windows 11/10 When I browse through forums I often find this question asked many times – I am unable to turn on Windows Defender manually or Windows Defender won’t or will not turn on and start in Windows 11, Windows 10, Windows 8, or Windows 7.
