Workaround: Restart your Computer
You can get the Engine unavailable error when your system did not boot properly. Therefore, as a workaround, you can perform a complete system restart to make sure all programs on your system start properly. Below have given the steps for restarting your computer:
1. Run the Windows Update Troubleshooter
Windows Update is a built-in feature in Windows that allows your system to detect and repair the errors found in it. Therefore, running a troubleshooter is a must in this situation. You can run the Windows Update Troubleshooter with the steps given below:
2. Restart Security Center Service
Security Center Service monitors your system and notifies you when your device is facing any errors. However, it can also cause issues with the Virus and Threat protection Engine. Therefore, you must restart the service to prevent the error from occurring.
3. Manually Enable the Windows Defender
Windows Defender provides additional protection to your system from viruses. When Windows Defender gets disabled, it will cause issues with the system. Therefore, you must manually enable Windows Defender through the command prompt.
4. Run the System Scans
Corrupted system files also give rise to this error. Therefore, make sure there are not any corrupted files on your device by performing system scans that will scan your device and repair the defective files. Below are the steps below to performing the system scans:
5. Change Windows Defender Registry Key Values
The Registry Editor consists of several registry keys with each key serving its own purpose. DisableAntiSpyware and DisableAntiVirus are special keys associated with the Windows Defender. When these registry keys are not set to the recommended number, you will face this error. Therefore, you must change the values of both registry keys by following the steps given below:
6. Temporarily Disable Third-Party Security Software
This error can also occur after inference from third-party security software such as Antivirus. Therefore, make sure that you temporarily disable any antivirus software installed on your system. Follow the steps below to see how to temporarily turn off an antivirus from our device (in this method, we have used Avast as an Example):
7. Delete conflicting Registry Entry
A corrupted Registry can also be one of the reasons for this error to occur as malware inside the Registry will create corrupted Entries that will prevent the Windows Defender from working. Therefore, you must delete these entries to prevent the Windows Defender Error. Follow the steps below to see how to delete the conflicting Registry Keys:
8. Manually Install the Windows Defender Update
Before you move to the last resort, you also have an option to manually download and Install the Windows Defender Update. Simply follow the steps below to see how to Download and Install the Windows Defender Update manually:
9. Perform a Clean Boot
If you are still facing the Virus and threat protection engine’s unavailable Error, then as a last resort, you must perform a Clean Boot which is a feature used to start your system on a minimal set of drivers and startup programs.
