Windows Defender Quick and Full Scans Fail After Seconds

If you haven't updated your Windows Defender, you should do so.

It's been discovered that the latest version of the antivurus software, which comes free with Windows 10, fails after a few seconds when it runs both its Quick or Full scans. And it only scans a few files - sometimes less than 10 at a time - during these failed runs.

This latest version of Defender - 4.18.1908.7 - was released earlier this week and it's this version that is affected by the'new' bug, which has replaced an old bug - introduced in July's Patch Tuesday - that caused the 'sfc /scannow' command to fail.

It appears that this problem isn't solely with Defender on Windows 10 and all other versions of Windows that use Defender have been affected. Should you need to, a Custom - manual - scan will bypass the issue.

The fix for Defender's issues was released in a Microsoft Security Intelligence update on September 19.