how to repair or reinstall microsoft defenders if malware has destructed it?

Hello @YUSRI IGNAS ,

Here are some troubleshooting steps that you can Follow -

1. Clean Up Residual Malware Effects Even after malware removal, leftover registry keys or scheduled tasks may continue to disable Defender. Use tools like Microsoft Safety Scanner or Malwarebytes to ensure the system is clean. Then you may want to also check and remove any suspicious scheduled tasks that may reapply restrictions.
2. Ensure Microsoft Defender Antivirus Service is Running. First, check the core service:
   • Press Win + R, type services.msc and hit Enter. This opens the Services management console. Ensure the “Windows Defender Antivirus Service” and “Security Center” are running and set to Automatic.
3. Verify and Secure Your System
   • Open Windows Security and turn on real-time protection. - If it is a black screen and throws an admin error, it might be worth checking this answer.
   • Run a full scan with Defender.
   • Re-enable Tamper Protection to prevent future unauthorized changes.
   • Check Windows Update to ensure Defender can receive updates.
   If none of this helps, please leave a comment below.
   If you find the answer above helpful, please Accept the answer to help anyone in the community who might have a similar question to quickly find the solution.