Open local files in Internet Explorer mode file extension allow list

This policy limits which file:// URLs are allowed to launch into Internet Explorer mode based on file extension.

This setting works when 'InternetExplorerIntegrationLevel' (Configure Internet Explorer integration) is set to 'IEMode'.

When a file:// URL is requested to launch in Internet Explorer mode, the file extension of the URL must be present in this list for the URL to be allowed to launch in Internet Explorer mode. A URL that's blocked from opening in Internet Explorer mode is instead opened in Microsoft Edge mode.

If you set this policy to the special value "*" or don't configure it, all file extensions are allowed.

To learn more about Internet Explorer mode, see https://go.microsoft.com/fwlink/?linkid=2094210

Example value:

.mht
.pdf
.vsdx