Registry reflection keeps the 32-bit registry view and the 64-bit registry view in sync on the target machine.

To enable registry reflection for all existing and new registry keys that are affected by the selected component, select No, which is the default value. If an end user installs a 64-bit application that has a component with registry reflection enabled, Windows Installer makes the associated registry changes in the 64-bit view of the registry, and the reflector copies the registry changes to the 32-bit registry view. Similarly, if an end user then installs a 32-bit application that modifies the same registry key or value, Windows Installer makes the associated registry changes in the 32-bit view of the registry, and the reflector copies the registry changes to the 64-bit registry view.

To disable registry reflection on all existing and new registry keys that are affected by this component, select Yes. Windows Installer calls the RegDisableReflectionKey function on each key being accessed by the component. This function disables registry reflection for the specified key. Disabling reflection for a key does not affect reflection of any subkeys.

Only 64-bit systems with Windows Installer 4.0 support this setting. Other systems ignore this setting.

For more information about registry reflection, see "Registry Reflection" in the MSDN Library.