Define the order of sources for downloading definition updates This policy setting allows you to define the order in which different definition update sources should be contacted. The value of this setting should be entered as a pipe-separated string enumerating the definition update sources in order. Possible values are: ?InternalDefinitionUpdateServer?, ?MicrosoftUpdateServer?, ?MMPC?, and ?FileShares? For example: { InternalDefinitionUpdateServer | MicrosoftUpdateServer | MMPC } If you enable this setting, definition update sources will be contacted in the order specified. Once definition updates have been successfully downloaded from one specified source, the remaining sources in the list will not be contacted. If you disable or do not configure this setting, definition update sources will be contacted in a default order.

[enable/disable]

(1) GPO: Computer ConfigurationAdministrative TemplatesWindows ComponentsWindows DefenderSignature Updates!Define the order of sources for downloading definition updates (2) REG: HKEY_LOCAL_MACHINESoftwarePoliciesMicrosoftWindows DefenderSignature Updates!FallbackOrder