How to reinstall windows security in windows 10 ?

As I told you, you will need to do a repair installation to replace Windows Defender. That malware deletes all its files and all the registry service configurations.

The FRST log shows the malware is gone, so you can proceed with the repair.

Go to: https://www.microsoft.com/en-au/software-download/windows10

• Just below "Create Windows 10 installation media" click on "Download tool now"
• Run MediaCreationTool22H2.exe and have it download the installation ISO file to your hard drive.
• Once it's downloaded, right click the ISO and select mount, then launch setup.exe
• Click on "Change how Setup downloads updates" and select the option "Not right now".
• If the option to "Keep personal files and apps" is greyed out, abort the installation.

I'm not sure what if anything you have installed is using IIS. Did you ever enable it? If not, you could always rename the inetpub folder to inetpub.bak and see if anything complains.

Unrelated to the above, the following program would have come bundled with K-Lite Codec Pack:

Infatica P2B Network

Uninstall it if you're not using it.

The ESD folder is just leftovers from the Media Creation Tool and can be deleted. :)

The malware that wiped out Windows Defender is still present. This procedure should remove it all, though it won't fix Defender. You're going to have to perform a repair installation when the malware has removed.

• Download Fixlist.txt and save it to the same folder that FRST64.exe is in
• Run FRST64 and click "Fix" - the PC will reboot to complete the removal

Please upload Fixlog.txt

Hello Yagyanta Acharya，

Welcome to the Microsoft Community！

Understanding that you want to know if reinstalling Security Center, we understand your confusion.

Usually, uninstalling the Security Center software itself will not result in data loss. Security Center software is mainly used to provide computer security protection and management functions, it does not directly store user data. Therefore, when you uninstall Security Center software, your personal data is usually not directly affected.

However, to ensure data security, it is recommended that you back up your important files and data before uninstalling the Security Center software. This can be used as a precautionary measure in case something unexpected happens.

To reinstall Microsoft defender, do the following:

1. you mentioned in your description that your Microsoft defender was uninstalled, just in case we can check if it still exists on your computer in settings:

Find Microsoft Defender in Settings>Applications>Applications & Features, click on the three dots on the right and select "Uninstall".

2. If you uninstall the application, it will not be automatically reinstalled. You can reinstall it manually by going to Microsoft Defender - Microsoft Apps and selecting "Install".

Disclaimer: Temporarily turn off real-time Microsoft Defender antivirus protection in Windows Security. However, keep in mind that if you do so, your device may be vulnerable to threats. So please turn it on immediately once issue fixed. 

Hope this helps,please feel free to reply me if anything is unclear or if there are any further updates, thanks.

Best Regards ,

Morning | Microsoft Technical Support Community