Microsoft Malware Protection Center releases security intelligence updates (a.k.a, definition updates) every 3-4 hours to update the virus definitions. However, your system may not automatically install every security intelligence update.
Windows Update automatically installs the Defender security intelligence update once per day.Read more
When you run a full scan using Microsoft Defender Antivirus, about 30 seconds to 1 minute into the scan, the CPU usage spikes and uses up all the remaining CPU. Its CPU usage remains at 100% throughout the full scan. The CPU fan becomes loud. Due to this issue, systems with heating issues may abruptly … Read more
In the aftermath of a malware attack, you often end up with unwanted exclusion entries in Microsoft Defender Antivirus. Exclusions may exist for a folder, file, file type, or process. These exclusions can be cleared by opening the Virus and Threat Protection page in Windows Security.Read more
Microsoft Defender Offline is an antimalware scanning tool that lets you boot and run a scan from a trusted environment. It utilizes Windows RE to run the offline scan.
During the Microsoft Defender Offline scan, it may appear to the user that the scan stalled or crashed at 91%, 92%, or 93% on some systems. This article tells you how to check if the last Microsoft Defender Offline scan was completed correctly.Read more
When you open Windows Security → Virus and Threat Protection → Manage Settings → Add or remove exclusions, you may be able to delete the exclusions by clicking on the “Remove” button.
Also, the Remove-MpPreference PowerShell command may not help.Read more
When Microsoft Defender Antivirus finds a virus, it asks you what action to take on the threat. The options are “Remove”, “Quarantine”, and “Allow on device”.
You may wonder:
The PowerShell cmdlet Start-MpScan starts a Microsoft Defender antivirus scan, but PowerShell offers no option to stop an ongoing scan. You may wonder how to cancel an ongoing quick/full scan started with Start-MpScan.Read more
When you enable the Local Security Authority protection in Windows Security → Device Security → Core isolation page on your Windows 11 22H2 (and higher) computer, the yellow exclamation continues to appear.Read more
The Windows Security tray icon provides a convenient way to run a quick scan, check for definition updates, or launch the Windows Security app quickly. However, in some systems, the icon may be missing from the notification area.Read more
When you open Windows Security, the security dashboard may show the message “You’re using other antivirus providers.” even though you don’t have any third-party antivirus program installed. In some cases, the real-time protection option would be available. But it reverts to “off” status immediately after you try to turn it on. If you open the … Read more