Windows Defender definitions update frequency  

How to set the Windows Defender definitions update frequency

You can set the frequency Windows Defender updates its definitions, natively in Windows Defender.

To do that you need to use PowerShell (as Administrator).

A. To set which day of the week Windows Defender updates its definitions , run the command: Set-MpPreference -SignatureScheduleDay <Day>
Where <day>:
Specifies the day of the week on which to check for definitions updates. Alternatively, specify everyday for a scheduled scan or never. The acceptable values for this parameter are:
0: Everyday
1: Sunday
2: Monday
3: Tuesday
4: Wednesday
5: Thursday
6: Friday
7: Saturday
8: Never
The default value is 8, never. If you specify a value of 8 or do not specify a value, Windows Defender checks for definition updates by using a default frequency.

Examples:
To update definitions every Friday enter the command:

Code:

Set-MpPreference -SignatureScheduleDay 6

To update definitions daily enter the command:

Code:

Set-MpPreference -SignatureScheduleDay 0

B. To set the frequency Windows Defender updates definitions, run the command: Set-MpPreference -SignatureUpdateInterval < Hours>
Where < Hours>:
Specifies the interval, in hours, at which to check for definition updates. The acceptable values for this parameter are: integers from 1 through 24. If you do not specify a value for this parameter, Windows Defender checks at the default interval, which is 24 (every 24 hours).

Examples:
To update definitions every 4 hours enter the command:

Code:

 Set-MpPreference -SignatureUpdateInterval 4

To update definitions twice a day:

Code:

 Set-MpPreference -SignatureUpdateInterval 12

C. To check that your Update definitions schedule has been set correctly , run the command:

Code:

 Get-MpPreference | select Signature*

To view all Windows Defender settings, run the command:

Code:

Get-MpPreference

For additional information for other Windows Defender settings, via PowerShell, please refer to Microsoft docs Set-MpPreference

That’s it. HTH!