Policy
Configure Multiple Display Mode
Enabling this policy allows to override the default behavior when connecting an additional monitor. It allows control over whether the display will automatically clone (mirror) the primary screen or extend the desktop. Extend expands the display onto the second monitor allowing to have different content on each screen. Clone duplicates the primary display onto the second monitor showing the same content on both screens. Internal Default uses the system's default behavior determined by Windows Settings.
340360fb478a DisplayConfigureMultipleDisplayMode Registry
Copy registry mappings
HKLM\System\CurrentControlSet\Control\GraphicsDrivers\Configuration\DefaultTopologySettingPolicy notes
Enabling this policy allows to override the default behavior when connecting an additional monitor. It allows control over whether the display will automatically clone (mirror) the primary screen or extend the desktop. Extend expands the display onto the second monitor allowing to have different content on each screen. Clone duplicates the primary display onto the second monitor showing the same content on both screens. Internal Default uses the system's default behavior determined by Windows Settings.