{"id":75146,"date":"2024-05-12T16:39:44","date_gmt":"2024-05-12T11:09:44","guid":{"rendered":"http:\/\/198.58.113.91\/blog\/?p=75146"},"modified":"2024-05-12T16:39:56","modified_gmt":"2024-05-12T11:09:56","slug":"defender-definitions-update-frequency","status":"publish","type":"post","link":"https:\/\/www.winhelponline.com\/blog\/defender-definitions-update-frequency\/","title":{"rendered":"How to Change Microsoft Defender Definitions Update Frequency"},"content":{"rendered":"

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.<\/p>\n

Windows Update automatically installs the Defender security intelligence update once per day.<\/p>\n

\"defender<\/p>\n

It lets you manually check for updates and install the latest definition updates as soon as they’ve been deployed via Windows Update.<\/p>\n

\"defender<\/p>\n

Other than Windows Update, there is a periodic signature update task named “Windows Defender Update” scheduled task that updates the definitions when the system is idle. This task is part of the automatic maintenance tasks<\/a> that run when the system is idle and automatically stops when user activity is detected.<\/p>\n

\"windows<\/p>\n

This task uses the Defender command-line tool mpcmdrun.exe<\/a> to update the definitions. The command-line it uses is MpCmdRun.exe SignatureUpdate -ScheduleJob<\/code>.<\/p>\n

\n

Please note that when the Defender scheduled task (“Windows Defender Update” – periodic signature update task) or the Windows Security app updates the definitions, they won’t appear on the Windows Update history page. But every update attempt is logged into the files c:\\windows\\temp\\MpSigStub.log<\/code> and c:\\windows\\temp\\MpCmdRun.log<\/code>.You can check the security intelligence version by opening Windows Security<\/strong> \u2192 Virus and threat protection<\/strong> \u2192 Check for updates<\/strong>.<\/p>\n

\"windows<\/p>\n

You can update the definitions from there, but it won’t be reflected on the WU history page.<\/p>\n<\/div>\n

So, typically, your system auto-updates the Defender definitions multiple times daily. However, the Windows Defender Update scheduled task doesn’t trigger if the system is idle.<\/p>\n

You wonder how to force Defender to update every N number of hours.<\/p>\n

Change Defender Definitions Update Frequency<\/h2>\n

The default frequency at which Defender updates its definitions should be sufficient for most users. However, if you need to increase the frequency of Microsoft Defender definition updates, use PowerShell.<\/p>\n

Launch PowerShell as administrator. For example, to force Defender to update the definitions every 5 hours daily, run the following commands:<\/p>\n

set-mppreference -SignatureUpdateInterval 5\n\nset-mppreference -SignatureScheduleDay 0<\/pre>\n
\"defender<\/p>\n
You may have to restart<\/strong> Windows for the changes to take effect.<\/p>\n
To revert to the Windows default settings, run:<\/p>\n
set-mppreference -SignatureUpdateInterval 0\n\nset-mppreference -SignatureScheduleDay 8<\/pre>\n
More Information<\/h2>\n
The “SignatureUpdateInterval<\/strong>” value specifies <time> as a number representing the number of hours between definition update checks. Valid values range from 1 (every hour) to 24 (once per day). If you do not specify a value for this parameter or set it to 0<\/strong>, Windows Defender checks at the default interval.<\/p>\n
The “SignatureScheduleDay<\/strong>” value specifies the day of the week on which to check for definition updates. Alternatively, specify everyday for a scheduled scan or never. The acceptable values for this parameter are:<\/p>\n