It can offer real-time protection from various threats like spyware, malware, and viruses to your PC.Once it scans and finds potential threats, this program will stop them.Step 1: Click Win and R keys on your keyboard to launch the Run box. Step 3: In the Services interface, search for Security Center service and right-click on it to choose the Restart option.Once this service is restarted, you can check if the issue -Windows Defender not starting is solved.
Alternatively, you can use a professional removal tool to uninstall your security applications, remove all files (including undetected files) and registry entries associated with the application, which may also prevent you from running Windows Defender.If Windows Defender will not turn on Windows 10/8/7 and runs into an unexpected error, perhaps there is something wrong with your system files. SFC, known as System File Checker, is a utility in Windows that allows you to scan for corruptions in Windows system files and restore them.How to scan your system files and repair missing or corrupted files? Step 1: Type cmd in the search box of Windows 7/8/10 and right-click on it to run this program as administrator.If those services aren't running well, the issue of Windows Defender not turning on will happen on Windows 10/8/7.
So, follow the instructions to restart necessary services, and here we will show you enabling Security Center service.
Step 2: In the Command Prompt window, type sfc /scannow command line and press the Enter key. This process will take some time, so please wait patiently until verification reaches 100%.