If restarting your machine fails to solve the problem, follow the troubleshooting steps below.

Hopefully, Windows Update will be able to drop in the latest Windows Security updates.

it’s possible for you to quickly repair your system files by running DISM and SFC.

Microsoft-Protection-Definition-Update-Failed

Wait until your machine finishes running the current command before entering a new one.

cycle your machine after running the commands above and see if you notice any changes.

Refresh the Windows Security Service

ensure the Windows Security Service is actively running on your machine.

run SFC command prompt

In that case, the issue should disappear afterclean booting your machine.

Basically, youre restarting your box using only a minimum set of drivers to prevent software conflicts.

Needless to say, avoid running two antivirus solutions at the same time.

Refresh-Windows-Security-Service

Then, run DISM and SFC to repair corrupted system files.

Additionally, refresh the Windows Security service, and reset the Windows Update components.

If the issue persists, run Disk Cleanup and clean boot your system.

run-disk-cleanup-windows-10