Always open PDF files externally
Supported on: Microsoft Edge version 77, Windows 7 or later
Registry
HKLM
Software\Policies\Microsoft\Edge HKCU
Software\Policies\Microsoft\Edge Value name: AlwaysOpenPdfExternally
Enabled: AlwaysOpenPdfExternally = 1
Disabled: AlwaysOpenPdfExternally = 0
Description
Disables the internal PDF viewer in Microsoft Edge. If you enable this policy Microsoft Edge treats PDF files as downloads and lets users open them with the default application. If Microsoft Edge is the default PDF reader, PDF files aren't downloaded and continue to open in Microsoft Edge. If you don't configure this policy or disable it, Microsoft Edge opens PDF files (unless the user disables it).