With version 1903 it is not possible to clear the log of protection history collected when false positive or real malwares are detected by this toy. One possibility is to use Powershell and see which items are listed and could be modified. To do this type Get-MpPreference.. In order to modity the delay of clearing potection history, the item related is ScanPurgeItemsAfterDelay and is set to 15 (meaning 15 days). To modify it at your choice then type in Powershell Set-MpPreference -ScanPurgeItemsAfterDelay N , set N as you want, mine is set to 1 day. Have a nice day. Coleo.