Some PC users have reported cases where the security information update for Microsoft Defender Antivirus doesn’t work on their Windows 11 or Windows 10 computer and the Windows security app. In the Virus & Threat Protection area, Engine not available It is displayed. If you are facing similar problem then this article is meant to help you with the solutions that you can apply to fix the problem.
When this issue occurs on your system, you may receive the generic Windows Update error code 0x80070643 or the more specific Windows Defender Update error code 0x80070643.
Virus & threat protection engine unavailable
Affected PC users who faced the issue Virus & threat protection engine unavailable problem after Windows Defender updates failed to install on your device Windows 11/10 also reported that clicking Upload updates as shown in the introductory image above it did nothing when updates tried to install but went back to the update loading state.
In any case, our recommended solutions given below should help PC users who have encountered this problem on their system to easily fix the problem to ensure Windows Defender definition updates are installed as soon as they arrive to keep their devices safe .
- Run the Windows Update troubleshooter
- Manually download and install the Windows Defender update
- Update Windows Defender via Command Prompt or PowerShell
- Restore Windows Security
- Roll back or repair Windows 11/10 in-place upgrade
Let’s take a look at the description of the process with respect to each of the solutions listed.
1]Run the Windows Update troubleshooter
Since definition updates for Microsoft Defender are shipped via Windows Update and the issue in question is related to the update, you can first run the Windows Update troubleshooter by following the steps below and see if it helps before delving further into the resolution some problems. not.
Windows 11
- press the Tap Windows + I to open the Settings app.
- Going towards System > Troubleshooting > More convenience stores.
- Under the Most frequently section, find windows update.
- Click it To run button.
- Follow the onscreen instructions and apply the recommended fixes.
Windows 10
- press the Tap Windows + I to open the Settings app.
- Go to Update and security.
- Click it Convenience store language.
- Scroll down and click Windows update.
- Click it Run the troubleshooter button.
- Follow the onscreen instructions and apply the recommended fixes.
Normally, this task should be enough to resolve most cases of Windows update related errors. In other cases, you can also run Microsoft Support and Recovery Assistant designed to help PC users troubleshoot Windows update installation.
Lis: How to use Windows Security in Windows 11 for better protection
2]Manually download and install the Windows Defender update
What’s important to know is that security intelligence is automatically downloaded by Windows Defender when it’s released. This way, the latest virus definitions are available on your device. However, if the definition update doesn’t install automatically, you can manually download and install the Windows Defender update.
To do this, you must first check if you are using a 32-bit or 64-bit version of Windows. Once you know the OS architecture, you can download the installers from the following links: 32-bit | 64-bit | BRAS – then double click on mpam-fe.exe file to run the package. The update links provided above point to the latest definition updates currently available for Windows Defender. Alternatively, you can identify the file KB number for Windows Defender definition update failed in Windows Update History at Definition updates section, then go to the Microsoft Update Catalog and find and download the standalone installer for the update package. Once downloaded on your system, you can run the installer to apply the update.
Note that you may not see any progress indicators or receive confirmation after installing the update. Therefore, you may need to restart your PC if after approximately 30-45 minutes the Virus & threat protection status does not appear. No action required with the green check mark.
3]Update Windows Defender via Command Prompt or PowerShell
There may be no obvious advantage over the GUI, but since the CMD prompt and PowerShell are barebones, operations launched in the environment are likely to be less prone to problems due to too many floating or unnecessary parts or processes. Then you can follow the instructions in the guide on how to update definitions in Windows Defender using Windows PowerShell or the guide on how to update definitions in Windows Defender using MpCmdRun.exe and see if the operation completes without problems.
4]Reset Windows Security
If virus & threat protection is not working normally as it should on your Windows 11/10 PC, possibly due to system corruption that is likely causing the problem, you can quickly reset the windows security app and see if that fixes it the problem. To perform this task, follow these steps:
- press the Tap Windows + R to invoke the Run dialog.
- In the Run dialog, type wt.exe and press Enter to open the Windows Terminal.
- In the PowerShell console, type or copy and paste the following command and press Enter.
Get-AppxPackage *Microsoft.Windows.SecHealthUI* | Reset-AppxPackage
- Exit the Windows terminal after running the command.
Related reading: Reset Windows security settings to their default values
5]Roll back or repair Windows 11/10 in-place upgrade
If nothing else works for you to fix the problem at hand, it is likely that a serious system corruption has affected the normal functionality of Windows Defender to install definition updates on your device. In this case, and as a last resort, you can reset your PC or do an in-place upgrade repair. Both tasks will restore operating system integrity by replacing corrupted system files which are essential for Windows 11/10 to function properly.
I hope you find this post helpful!
Why can’t I open my virus & threat protection?
If your virus & threat protection has stopped, in most cases this is usually due to the fact that you have corrupted system files, which you can attempt to fix by running an SFC and DISM scan to check for file-level corruption system and fix them to solve some difficulties, such as Windows Security app problem.
Lis: Quick scan not working in Windows Defender
How do I reset my virus and threat protection?
If you are sure on your Windows 11/10 device that a file quarantined by Windows Defender is not a threat, you can recover the item by following these steps:
- Open Windows Security.
- Select Virus & threat protection, then click Protection history.
- In the list of all recent items, filter out quarantined items.
- Select an item you want to keep and take an action, such as restore.
Now read: Windows Defender: This setting is managed by the administrator
